History and Theory of Psychology: An early 21st century student's perspective

Paul F. Ballantyne, Ph.D. 2008©pballan@comnet.ca

Table of Contents

Introductory Comments: Notion of history, theory, and methodology for the student of psychology

Preliminary Definitions and Distinctions

Theory and Knowledge in the "Standard" versus the "paradigm" view of scientific practice

Where does the discipline stand today?

On surmounting the "insider vs. outsider" divide

Section 1: From the Presocratics to Aristotle: Fundamental issues and the theoretical imperative

Ancient Greek Culture and the Presocratic Philosophers

Socrates, Plato, and Aristotle

Concluding Remarks for Section 1

Section 2: From Bacon to Kant: Science and Psychological Themes

Francis Bacon's Optimism

Importance of Galileo to Psychology

Context and Reasons for Descartes' Mind-Body Dualism

Classical British Empiricism

The Kant versus Hume debate and its importance for Psychology

Concluding Remarks for Section 2

Section 3: Bridging The Gap: British Associationism, Psychophysics, and the Founding of a Discipline

British Associationism

Müller's Vitalism, Fechner's Psychophysics, and Helmholtz on sensory elements

Wundt, the Leipzig laboratory, and his rebellious students

Concluding Remarks for Section 3

Section 4: Evolution and Psychology: In Darwin, Romanes, Morgan, James, Dewey, and the Chicago Functionalists

Darwin's Organic Evolution and Mental Continuity Doctrine

Romanes and C.L. Morgan (Cultural evolution recognized)

James, Lewes, and Dewey

Whatever happened to "Functional" Psychology?

Concluding Remarks for Section 4

Section 5: Wax and Wane of American General Psychology (1920-1990s): S-O-R, the Operationist Variable model, and the Crisis of Relevance

From Watson's S-R to Woodworth's middle of the road S-O-R

Rise of the "molar" S-O-R formulas and early Variable models (Woodworth and E.C. Tolman)

Rationale and limits of the combined operationalized variable model

Variable psychology and the anthropology of the abstract individual

Crisis of Relevance

Concluding Remarks for Section 5

Appendix 1: Political, Religious, and Economic Aspects of Western Culture

Appendix 2: Basic Philosophical Choices, metatheory, and theory assessment methodology for a unified 21st century psychology

Appendix 3: Varied Positions on the Mind-Body Relation in Psychology

Appendix 4: Subject Matter and Method According to Classical Psychological System

Selected Bibliography

History and Theory of Psychology: An early 21st century student's perspective

Paul F. Ballantyne, Ph.D. 2008©. pballan@comnet.ca

Section 1:

From the Presocratics to Aristotle: Fundamental issues and the theoretical imperative

Now the Introductory Comments have been presented we can move into a roughly chronological account of various past eras of thought or practice which influenced the development of psychological science. The first of the five Sections to be presented is called "From the Presocratics to Aristotle." Although this relatively brief Section takes us way back to the 6th-3rd century BC, it will become apparent that many of the fundamental ontological, epistemological, and methodological issues raised during the ancient period of combined philosophy and practice are still with us in various modern or postmodernized versions.

The "theoretical imperative" requiring us to make informed choices between holding one position over another is also still with us (Tolman, 1999a). At some point in each of your careers, it will become incumbent upon you to adopt, apply, or even advocate a theoretical position which assumes: either a strictly "quantitative" distinction between physiological and psychological processes or a "qualitative" distinction as well; either the "fallibility" or the "trustworthiness" of perception; either determinism of personal deportment from "outside forces" (e.g., environment, innate ideas) or a relative freedom and control over one's actions according to ongoing forward-reaching "goals," internalized "motives;" and the like.

Our rationale for reaching back to cover the Ancient Greek philosophers, therefore, is to provide you with a brief acquaintance with how others have dealt with such fundamental issues and with the eventual practical outcome of their adherence to one theoretical view over another. Raising such issues in this safe third-hand manner gives you the opportunity, so to speak, of trying on each position for size without having to worry about suffering the direct repercussions (both personal and professional) of choosing one path over another on your own.

Ancient Greek Culture and the Presocratic Philosophers

As Bertrand Russell's A History of Western Philosophy (1946) points out, philosophy and practical science were not originally separate. They were born together in the beginning of the 6th century BC and they both involved a transition from a theistic toward a natural way of thinking about the world.

Around 800 BC, following a long period of war the ancient Greeks reacquired a written language and by 750 BC two Greek poems the Iliad and the Odyssey (attributed to Homer) were written down. In Greek myths, regarding the creation and deeds of the gods, statements about cosmological topics (e.g., creation and structure of the universe) appeared only incidentally and by implication.

The Homeric gods were the gods of a conquering aristocracy, not the useful fertility gods of the Egyptians or Babylonians. Although the gods of most nations claim to have created the world, the Olympians made no such claim. The most they ever did was conquer it. According to Hesiod (750-700 BC) a farmer who tried to systematize the varied ancient myths into a "Theogeny" these divine constituents of the universe were personal beings. Their occasional causal interventions into universal events or interest in human affairs were likewise personal, self-serving, and motivated by sexuality, hatred, jealousy, and so forth.

Subsequent Greek thinkers, from the ones we now call the "Presocratic philosophers" onward, were particularly interested in the universe (in questions regarding its origin, its fundamental elements, and its ongoing development). In

order to ask the kinds of ontological questions they did, they had to make a break with this former mythological way of thinking (see Kirk, Raven, & Schofield, 1983). Russell (1946) reports there were two tendencies at play in this chapter of Ancient Greek culture. One was passionate, religious, mystical and otherworldly. The other was cheerful, empirical and interested in acquiring knowledge of diverse worldly facts. To a point, the early Greek philosophers -from Thales in the 6th century BC, right up through to Aristotle in the 3rd century BC- represent this latter tendency.

The Greek World 5th-4th century BC (From: Lloyd, 1970).

"As Greece is a mountainous and rather barren country, its inhabitants have been obliged from remote times to seek new lands that would offer them work and prosperity. At the beginning of the sixth century BC (Before Christ), we find one winding series of coastal colonies, extending from the coast of Asia Minor to Africa, to Spain and to southern Italy. Here the Greeks were so numerous that they outnumbered the inhabitants of Greece properly so called, and hence the name Magna Graecia was given to this far-flung territory. The colonies, favored by democratic liberties and economic well-being, and moreover having contact with a greatly advanced civilization in Persia and Egypt, had an opportunity to develop their own sense of culture.

Among the Grecian stocks which have contributed greatly to the formation of philosophy is the Ionian strain, which was spread through Asia Minor, the islands of the Aegean Sea (Ionia), and southern Italy and Sicily. It is among the Ionian colonies of Asia Minor that the story of philosophy takes its beginning, because it was in the flourishing city of Miletus that the first three Western philosophers were born and lived: Thales, Anaximander, Anaximenes" (Description: From a "Radical Academy" site).

Thales (625-545 BC)

By convention Presocratic philosophy is said to begin with Thales who can be dated only because he predicted a solar eclipse, which (according to astronomers) occurred in 585 BC. This citizen of Miletus (a commercial city in Asia Minor with trade links to Babylon and Egypt) is said to have declared the "world is made of

water" and to have held that the transformation of this fundamental substance is the source of all living things.

It is important to note that this first cosmological metaphysic is not only ontologically materialist and empirical but also contains an implicit view of dynamic motion and change. Water can be seen to be transformed from a liquid into other states. By evaporation water turns into steam and hence apparently into air. Water also freezes to become solidified ice. Further, both processes can be reversed. Rain, dew, and condensation were recognized as a return of water from the air and melting snow likewise turns a solid into a liquid. Thales used these commonly observable facts to postulate that things were water all along.

Two successors of Thales (also from Miletus) retained a material monist metaphysic but differed from him regarding the details of their cosmological view. Anaximander (610-547 BC) doubted whether any fundamental substance would exist in an observable pure form, because it would not only be "timeless" but also "overpowering." Anaximenes (585-525 BC) suggested that air is the fundamental substance and that observable objects differ in the "quantity" of air contained therein.

Heraclitus (540-480 BC)

Heraclitus (of Ephesus) was the first philosopher we know of to both emphasize the general process of change in nature and to analyze (carefully) their particular manifestations. He is best known for two important general positions:

(1) the Heraclitean "doctrine of flux" which viewed the whole cosmos as in a constant state of change. He expressed this view poetically as a metaphor: "You cannot step twice into the same river; for fresh waters are ever flowing in upon you" (Fragment 91).

(2) his disagreement with Thales about the basic fundamental element. For Heraclitus, the fundamental element of the universe was fire not water.

Starting out with a materialist position similar to that of Thales, Heraclitus went beyond mere debates over fundamental substance by suggesting that the important aspect of the cosmos to account for is its varied dynamic transformations -e.g., ice to water and water to clouds. Fire, he reasoned, is a more fundamental element than water because it is fire (in the sun, or in a forge) which transforms solids into liquids. This fire itself is very active and so too is everything else in the world.

Like the earlier Ionians, Heraclitus takes his general stand on a clearly materialist ground: "This world which is the same for all, was made by no god or man. It has always been, it is, and will be an ever-living fire. Kindling with measure and being quenched with measure" (Fragment 30).

His specific ontological position is a relational materialist monism achieved by accepting the internal contradictions of particular things (rather than an "absolute," unchanging, or

timeless monism). In the process of transforming from one state into another, or from one element into another, there is always contradiction within the object being transformed. Consider, for instance, fuel burning in a fireplace: There is a point at which the fuel is clearly a log and a later point at which it has been changed into smoke and ash. But during the transition (where the fire is), it is smoke, ash, and log. Or said another way, neither merely smoke, nor ash, nor log. The fuel of the fire is what it was and what it will be.

In other words, like Thales, Heraclitus viewed this cycle of changing diversified elements as a unity, but in contrast to Anaximander it was not a timeless, unchanging, or absolute pattern. Why? Because the particular principles of change are actually internal to the varied nature of the stuff of the universe itself. Change in any particular object is not merely imposed upon it from outside by some initial timeless or overpowering substance, but is rather to be understood by us by way of our careful metaphoric reasoning and reference to that object itself. The unity in the diversity of the river we are wading in is not timeless (absolute) or imposed upon it by fire but develops along with the age and changing course of the river over time.

By utilizing this dynamic kind of reasoning about both general and particular aspects of nature, Heraclitus recognized all apparently fixed states of being as part of a varied process of perpetual "becoming" (in which every object enters existence, stays for a while and passes away). He also went well beyond the predominantly cosmological topics of his Miletian predecessors to considered diverse life phenomena (e.g., sleeping-waking; hunger-fullness; youth-age; and life-death relations). For instance, in considering "life," Heraclitus argued that death is a pervasive feature in our lives. If all things are changing and if change is death to the old and birth to the new, then strictly speaking we have constant experience of death. Just as the river is always changing, so too does everything else including ourselves.

Anaxagoras (500-428 BC)

Anaxagoras of Clazomene (on the Lydian coast of Asia Minor) was the last of the great Ionian philosophers and first to choose Athens as his home. He was a teacher and friend to Pericles (495-429 BC), the famous Commander-in-chief of Greece (for fifteen terms) during a period considered to be the height of that civilization.

Anaxagoras is know to have laid down his cosmological views in a prose work, "On Nature," written in the Ionic dialect. Only fragments of this work, however, have survived as quoted and interpreted by others.

With regard to the ongoing fundamental element debate, he postulated a near infinite materialist monism by arguing that in anything there is a "portion of everything." By this he meant that even the smallest speck of dust contains some portion of each element. These elements (translated variously as "germs" or "seeds") included not only earth, air, fire, and water; but also blood, gold, hair, and bone. Contained in each such material "seed" are the traditional analytical opposites (a.k.a., qualities) of hot and cold, wet and dry, and also "color." It is of these inherently unified attributes and qualities of matter itself that he is expressly speaking when he says that the things in the "one world" are not truly cut off from one another as if by a "hatchet."

Any observable object is a "mixture" in which one such element may "predominate," thereby determining that object's appearance and allowing its classification into a rough typology (like solid, liquid, or vapor). This is often described as Anaxagoras’s ontological "principle of predominance." Although this term succeeds in stressing the quantitative arrangement aspect of his account, another central qualitative relational aspect should also be appreciated. That is, according to Anaxagoras, observable objects differ qualitatively and these qualities reside within the elements of which they are composed to varying quantitative degrees. Thus, for Anaxagoras, a piece of metal in which gold predominates quantitatively is called "gold" and when it is melted it retains its qualitative yellowish hue. Likewise, though somewhat paradoxically, even a piece of snow (which appears white) is at least partially "black" for when it freezes to become ice or melts to become water, both products are "darker."

In other words, the apparent logically paradoxical ontological statements by Anaxagoras (regarding both the qualitative transition from an initially "undifferentiated mass" to a differentiated and "orderly" cosmos containing "planets;" as well as his statements regarding the source of the qualitative attributes of objects as residing within their elemental material "seeds") are best understood or analytically resolved by recognizing that (like Heraclitus) Anaxagoras was motivated by an attempt to grasp and accept the objective contradictions of material existence wherever he might find them.

One of the most notable qualitative (objectively contradictory) aspects of nature which Anaxagoras tackled was the distinction between "living and non-living" matter. Here, he is sometimes suggested to have made an exception to his otherwise broadly applicable and characteristically Ionic "materialist" position by way of introducing the concept of "nous" (generalized sensitivity, minding, or reason). Nous is conceived by him as a special substance, liquid, or power that is present only in living beings and distinguishes them from non-living or dead matter. Although the other elements contained in objects have a proclivity to "mix or divide," nous is considered to be a more uniform, pure, indivisible, and perhaps even immaterial property or power of living matter. It is, presumably, present in plants (which bend toward light) but is most certainly present in animals and man.

The presence of nous in animals is considered by Anaxagoras as the source of their motility and its presence in human beings allows us to appreciate (or attend to) the structured order, pattern, and sequential arrangement of the world around us. It is not clear though, whether Anaxagoras fully broke with the tradition of earlier materialist explanation by going so far as Parmenides (504-456 BC) to suggest that the observable order or mechanical motion of physical objects through space was mentally imparted.

In any case, concerns over the inconsistencies of Ionian views on order, arrangement, change, and causation led to the articulation of a set of logical paradoxes regarding motion by a student of Parmenides called Zeno. Zeno of Elea (490-430 BC) argued that if we see things in motion and our analytical theory of the universe does not allow such motion, then our senses must lie. He therefore postulated a Block Universe with no real change or motion (a static form of "absolute monism") which created much difficulty for later thinkers.

Take, for example, the so-called paradox or "argument of Achilles" in which the hero of the winged foot (Achilles) is seemingly mismatched with a turtle (symbol of slowness) in a running race. Analytically speaking, even if this gallant hero gives the turtle a suitable handicap of time and space by which to start the race, it is conceivable that he may never overtake his slower opponent. Let us supposed that at the start of the race this interval between Achilles and the turtle is twenty feet, and while the hero runs twenty feet, the turtle advances only one foot. Achilles, it is

said, cannot reach his running mate because while he runs twenty feet the animal moves one foot and while he runs a foot his rival will have scurried one-twentieth of a foot, and successively, while Achilles proceeds one-twentieth of a foot the animal will have traveled one-twentieth of a twentieth of a foot, and so on ad infinitum.

A similar sort of analytical paradox regarding time, space, and motion is encountered in the "example of the arrow" which will never reach its target. Before striking the target, the arrow must traverse half the distance, and before it reaches half this space it must traverse one-half of this half, ad infinitum. Thus the arrow remains (analytically) ever at the same place, no matter how much it may seem to be displaced to the eye. Such Sophistic arguments, as Aristotle later noted well, are based on a false prejudgment that space is (in fact) made up of an infinite number of analytically discrete and separate parts.

Anyway, let's return briefly to Anaxagoras and his seemingly equivocal ontologically materialist concept of "nous". One easily referenced indication that "nous" (which is typically translated as simply "mind" but which seems to mean far more than that to Anaxagoras) was introduced by him as a valid recognition of something that needed to be explained -i.e., the distinction between living and dead matter as well as the observable sequential arrangement of worldly events- but for which there was still too much ignorance to provide an explanation as such, comes from Socrates. Socrates, who, as we will see adopts an unequivocal ontologically idealist metaphysic makes the following derogatory remarks about Anaxagoras:

"I once heard someone reading from a book, as he said, by Anaxagoras, and asserting that it is mind [nous] that produces order and is the cause of everything. This explanation pleased me. Somehow it seemed right that mind should be the cause of everything....

I lost no time in procuring the books, and began to read them.... It was a wonderful hope, my friend, but it was quickly dashed. As I read on I discovered that the fellow made no use of mind and assigned to it no causality for the order of the world, but adduced causes like air and aether [fire] and water and many other absurdities" (Socrates in Plato's Phaedo, 97b-98c; In Hamilton & Cairns, 1961, p. 80).

These so-called "absurdities" are, of course, the materialist explanations that we now identify with the early Ionic Greek philosophers. So, at least by the assessment of Socrates (through Plato), the approach of Anaxagoras was not a radical departure from the general materialist trend of his era.

I don't think we really have to worry about which portrayal of his reliance upon "nous" is ultimately correct in this regard. It is enough for us to simply note, that -for whatever reason- we have in Anaxagoras this first instance of an appeal to an abstract ordering principle concept for explanation. In having introduced "nous," Anaxagoras had not just introduced a new or wider definition for an older word, he had done something which the previous Ionians up to this point had not done: He appeals to an albeit tentative and as yet abstract mental concept to reassert a natural fact of existence -i.e., the observable structure, order, or sequence of changing worldly events.

Empedocles (490-435 BC)

Empedocles of Acragas (on the south coast of Sicily), was at various times a democratic politician, mystical philosopher, and miracle-worker who also eventually claimed to be a god. He is best known for systematizing the

"doctrine of four elements" (water, fire, air, and earth) and their "qualities" (hot, cold, wet, dry) which dominated popular thinking for two thousand years thereafter. Although this cosmological position was both a statesmanlike compromise between the conflicting views of the Ionians (Thales-Anaxagoras) and shared their naturalistic ontology, it differed from it because Empedocles considered these elements as analytically separable (as a "plurality" which form no actual unity).

Any particular object contains a "chaotic" and conflicting admixture of different proportions of each analytically separate element. Like Anaxagoras, Empedocles held that the qualities exhibited by a particular object are determined by the proportional mixture of elements which it contains, but (unlike Anaxagoras) he believed these qualities to be an outcome of the relations between those elements and not to reside in the elements themselves. Such qualities as color, coldness, etc., were viewed as a special resultant of the specific mixture of elements and not a property of the elements or even of the object per se.

Change in the cosmos was produced by two fundamentally abstract and anthropomorphized forces "love and strife." The first was the cause of combination (or rather congealment). The other was the cause of separation. Empedocles attempted to explain cosmic nature, the functions of the human body, and the activities of the "soul" as resulting from these conflicting active forces.

He did not share Parmenides' distrust of the senses and produced the first (inside-outward) version of various subsequent "emanation" hypotheses to account for our visual contact with objects (see our coverage of Aristotle below who argued against all of these).

Empedocles is also said to have utilized observational methods -e.g., a water clock & bucket; and whirling cup on a string- to argue not only that air is a separate substance but also to illustrate the related physical principle of centrifugal force. It must be pointed out, however, that in both drawing conclusions from observation and in his assertion of an absolute plurality of elements, Empedocles was hampered by a very prevalent lack of distinction at the time between what would later be called the logic of discourse and the logic of being. This confusion between discursive argument and being seems to have extended itself into his personal life. After having been banished from Acragas for proposing charlatan-like claims, he is said to have leapt into the fiery crater of Mt. Etna to prove he was a god.

Democritus (460-360 BC)

Democritus (of Abdera in Thrace) was a contemporary of Empedocles, Zeno, Socrates, and Plato. The details of how his materialist ontology or views on cosmological change (motion) differed from his contemporaries are rather important because they are played out again in various eras of subsequent scientific endeavor. Democritus is best known for his doctrine that the world is made of "atoms" (which means indivisible) and for his suggestion that our ability to split objects up into sections (e.g., carving up an apple) implies the existence of a "void" between these indivisible aspects of the material universe.

Democritus is also credited with having proposed a "substantive" theory of mind (see Morris, 1932) along with a second (outside-inward) version of the emanation hypothesis to

account for our contact with observable objects. Yet since his theory of mind was intimately tied to his active view of material substance, we will have to return to it only after considering how this more central ontological aspect of his philosophy fits into the ongoing and subsequent course of Greek thought.

First of all, while Empedocles considered his four elements as analytically separate (as an absolute plurality which congeal but do not truly combine or transmute), Democritus proposed an explicitly materialist "monism" which bridged the logical gap between diversity and unity by returning to the "dialectical" insight of Heraclitus (and Anaxagoras). That is, with regard to the relative ontological relation between objects and their constituent elements, the one is many and the many is one. To put this another way, Democritus seems to have recognized "objective contradiction" in nature.

Furthermore, like Heraclitus, he recognized that matter and motion are different yet they are identical. This appreciation of the unity of such differences emboldened Democritus to suggested (in a similar manner) that the inherent activeness of atoms was the fundamental origin of all change in the cosmos.

Thus while he postulated that such "active atoms" are alike (in their indivisibility) and differ from one another only in terms of "quantity" (size, smoothness, or speed of resonation), he also acknowledged the possibility that an orderly combination of such "like" elements might somehow produce the vast array of palpable objects or perceivable events we deal with in our ordinary lives. As Russell points out, however, the middle part of the latter comment (regarding quantity) is debatable because we only have fragmentary writings and secondhand accounts of Democritus -predominantly from Aristotle- to rely upon. It is traditional though to contrast Anaxagoras who seems to place "qualities" (like color) in the elements (or "seeds"), with Democritus who (after the fashion of Empedocles) seems to deny that they reside in "atoms."

We do not know if Democritus explicitly addressed the major concerns of his fellow-townsman Protagoras (480-410 BC) regarding the "one-sided" relationship between elements and "qualities" characteristic of most of the early Ionic naturalists. That is, if objects have observable qualities (e.g., color, shape, texture) and elements or atoms don't, then: "Where do these qualities come from?" Protagoras suggested that according to the arguments of the Ionians (and Democritus), these qualities come from the "senses." Furthermore, suggests Protagoras, if their implied theories are to be taken literally, "man is the measure of all things" (see Schiappa, 1991; Tolman, 1995).

Whether or not Protagoras was truly the first "Sophist" (of the sort later vilified for holding that no truth is to be had from intellectual argument), it was in this manner -of drawing out the implications of earlier overzealous claims- that the original "ontological" concerns of the Ionians (and Democritus) were redirected toward the "epistemological, logical, and ethical" concerns of subsequent philosophical thought. Ancient Greek Sophism, we will simply note here, is our first exemplar of an explicitly combined "subjective idealist" ontology and "anti-realist" epistemology in which the latter is nearly absolutized. For the Sophists and their clientele (see below), the art of individual argument was made the central emphasis of methodological concern. Their focus was on the manner by which personal opinions and convictions are formed or transmitted to others by way of persuasive discourse (epistemological and logical questions) rather than with ascertaining the place of human kind in the cosmos (ontological questions) or even with those epistemological aspects of a given debate which touch on the truth of the opinions or convictions being debated.

Socrates, Plato, and Aristotle

The respective contrasts between the Sophist's position and that of Socrates who kicked-off the "Classical period" of Greek thought by proposing a distinctly objective idealist and indirect realist position, as well as with the similar views of Plato and Aristotle (who elaborate the Socratic position further) will be our main concern for the remainder of this Section.

Socrates (469-399 BC)

Socrates (of Athens) taught verbally and did not put his doctrines into writing. We must, therefore, rely on conflicting accounts from his students to reconstruct his life and philosophical approach. All such sources agree, however, that Socrates (the son of a stonecutter and a midwife) was exceedingly ugly, had an unorthodox (lowly) manner of dress and often wandered around barefooted.

Socrates was born in the year following the end of a 20 year war in which the army of Sparta and the navy of Athens had combined to fight off a bid by Persia (under Darius and Xerxes) to turn Greece into a colony of their Asiatic empire. After the war, Sparta demobilized, returned to its tradition of xenophobic seclusion and declined economically. The city-state of Athens, however, turned her navy into a merchant fleet and prospered.

"Sparta relapsed into agricultural seclusion and stagnation, while Athens became a busy mart and port, the meeting place of many races... and of diverse cults and customs, whose contact and rivalry begot comparison, analysis and thought" (Durant, 1933, p. 8).

Unlike the Sophists (who were paid for teaching a new class of wealthy economic aristocrats the skills of oration and persuasive argument), Socrates charged no fees and taught students (including women) from various walks of life. He owned a modest home in Athens and drew on a yearly income from moneys wisely invested with one of his business-minded pupils.

Socrates is best known for the technique of artful questioning he employed -now called "Socratic dialogue." In such dialogue, teachers help students to define their discursive terms exactly and thereby discover for themselves the implications of holding one position over another. Socrates is said to have demonstrated the utility of this leading-questions technique by helping an uneducated slave to discover the Pythagorean theorem regarding the square-root on the hypotenuse of a right-angle triangle (see Plato's Meno).

In contrast to the Sophists, Socrates believed that a distinction could be made between "appearance and essence." According to Plato, the latter entailed an acquaintance with "absolute" truth gained through skillful argument. Despite conflicting accounts of his view on truth it is well-known that Socrates was primarily concerned with issues of ethics ("virtue" and "right action"). His fundamental argument is that the route to virtue is "self-knowledge" because no man sins wittingly. Essential knowledge, as contrasted to easily attained "apparent" knowledge, leads inexorably to virtue and can be found in the mind. Whether absolute or otherwise, his ontology is clearly an objective idealist one -where truth needs only to be "drawn out" of the mind and clarified by skillfully guided discourse.

Relatedly, his implied epistemology is of the "indirect realist" variety. Let's note that the above demonstrative example of his technique of helping people dredge the truth up out of their mind is not one about ethics, but is one about "being"; about some aspect of the real world. The Pythagorean theorem is one that pertains to the

way reality is structured on a two-dimensional plane. The Sophists had attempted to counter the early Ionian or Miletian philosophy (of naive materialist ontology in the absence of any systematic epistemology or logic) by replacing it with a form of argumentative discourse in which epistemology was totalized. This was a troubling development which Socrates set out to correct for various reasons.

Since this is our first openly confrontational encounter between such "subjective vs. objective idealist" positions, it will probably be instructive to provide a selected passage from Socrates which indicates the relevant contrast. Here, Socrates (in Plato's Theaetetus) is conversing with a student of Protagoras called Theodorus. During that exchange of views, Socrates produces the following reductio ad absurdum of the Sophist's position:

"Socrates: Well then Theodorus, shall I tell you a thing which surprises me about your friend Protagoras?

Theodorus: What is that?

Socrates: The opening words of his treatise. In general, I am delighted with his statement that what seems to anyone also is, but I am surprised that he did not begin his Truth with the words, 'The measure of all things is the pig, or the baboon,' or some sentient creature still more uncouth. There would have been something magnificent in so disdainful an opening, telling us that all the time, while we were admiring him [Protagoras] for a wisdom more than mortal, he was in fact no wiser than a tadpole, to say nothing of any other human being.... If what every man believes as a result of perception is indeed to be true for him; if, just as no one is to be a better judge of what another experiences, so no one is better entitled to consider whether what another thinks is true or false, and, as we have said more than once, every man is to have his own beliefs for himself alone and they are all right and true – then, my friend, where is the wisdom of Protagoras, to justify his setting up to teach others and to be handsomely paid for it, and where is our comparative ignorance or the need for us to go and sit at his feet, when each of us is himself the measure of his own wisdom? Must we not suppose that Protagoras speaks in this way to flatter the ears of the public? I say nothing of... the ludicrous predicament to which... this whole business of philosophical conversation [is brought by adherence to such a proposition], for to set about overhauling and testing one another's notions and opinions when those of each and every one are right, is a tedious and monstrous display of folly..." (Socrates from Plato's Theaetetus, 161b-e; In Hamilton & Cairns, 1989, pp. 866-867).

Socrates is pointing out to Theodorus that even though Protagoras may succeed in drawing or swaying a crowd, the fundamentally subjective position being assumed by Sophism itself is ultimately self-undermining. For example, if during the course of some heated discussion I become tired of the dispute and blurt out "well, we each interpret these events in our own way," there appears to be very little left to talk about. If you try to counter with "no we don't, there are certain indisputable facts to be considered here..." etc., I would be wise to grant that's true "for you." I haven't won the argument, nor lost it, but at least you've fallen quite nicely into the epistemological trap I set. This being the case, there is no remaining ground for our common inquiry into the matter originally under dispute, nor motivation (at least on my part) for further argument. Whether we were discussing Ancient Greek history or this week's departmental gossip, such off-putting tricks of argument are the stock and trade of the Sophist both ancient and modern. They are designed to throw one's opponent off balance, end discussion, or amuse a crowd and most usually nothing more. Parenthetically, had you avoided the trap by taking the maddening though effective Socratic tact of insisting that I clarify more fully what I mean by "interpreting" the events, then I would have been in trouble. That's one way to beat the Sophists at their own game!

So in the face of such subjective idealism (along with all its inconsistent anti-realist indeterminacy), Socrates offers up for us an objective idealist position in its place. According to him, there is truth, and it is about nature as well as about virtue -because human virtue (as indicated below) is for him always to be considered with regard to our relation to the real and social world within which we live. But according to Socrates, truth (a.k.a., "essential knowledge" of the real world) is not discovered by referring directly to the material world, it resides within our own mind and is ascertained by engaging in reasonable deliberations with oneself or carefully defined assertions with others.

To the modern reader who is encountering this "objective" variety of ontological idealism for the first time, it might seem quite problematic as to how such knowledge got there in the first place. Be assured, however, that the position of Socrates is but a mere starting-point or anticipator of more fully worked-out versions of that particular metaphysical position. Some of those later versions will mobilize an appeal to "innate ideas", while others appeal to an orderly structure of "sensory phenomena" or common "experience", and still others will rely on so-called "a priori categories" to provide their respective accounts of why objective knowledge is to be sought in the mind. All we need be concerned with now though is preparing ourselves to encounter some rather convincing versions of objective idealism, each of which find their roots and share their limitations with the Classical Greek positions of Socrates, Plato, or Aristotle.

Returning to his related account of human nature and virtuous action, Socrates is notable for the non-elitist progressive flavor of his views. A proper assessment of human nature is not achieved by considering the merits of men or women as isolated groups (e.g., by gender) nor even as individuals, but rather by way of considering with whom and how they associate socially as well as with careful regard the kind of state or historical era within which they reside.

Thus, for Socrates, the apparently diverse issues of whom to marry as well as "who is best suited to fix shoes, mend ships, or run the ship of state" were essentially the same. He proposed that to make such decisions or to perform any of these societal tasks competently requires self-knowledge and humility. Further, he suggests that no special reverence should be afforded to those who overestimate their own inherent worthiness in any of these pursuits.

Socrates applied this latter irreverential doctrine as closely to himself as to others. Upon being named by the Delphic Oracle "the wisest of all philosophers," he denied this to be the case and then began circulating among pretentious people of various professions (including politicians, poets, and artisans) to question their knowledge. He concluded none of these fellow-Athenians were knowledgeable and suggested that the only difference between himself and them was that he recognized his own ignorance.

This irreverence for established authority and social hierarchy was viewed as a challenge to the only recently reestablished political balance of the era (see below) as well as an affront to the mildly conservative sensibilities of "ordinary" (slave-owning) democratic citizens in Athens. A decision was eventually made to silence the now 70-year-old philosopher, partly because one of his former students (called Critias) had just carried out a failed armed uprising. Upon being accused of corrupting youth by his teachings, Socrates both annoyed the court by accusing them of "eloquence" (arrogance) and then refused to plea-bargain in any way that would openly admit intentional guilt. He accepted the resulting sentence of death with equanimity and willingly drank the deadly hemlock potion in the presence of his students.

Plato (427-347 BC)

In contrast to the lowly Socrates, Plato was a cultural aristocrat in both birth and political sentiment. He was born in Athens and enjoyed a privileged childhood during the early years of the generation-long Peloponnesian War with Sparta which Athenian democracy eventually lost in 404 BC. During an era in which large landowning aristocrats and then Spartan-imposed military Oligarchs were being successively edged out of power by a disorderly though democratic citizen Ecclesia (general assembly), Plato was frustrated in his initial youthful efforts to enter politics. Quite early on, therefore, he was drawn to the teachings of Socrates who scorned such amateur "mob rule" for its incompetence.

Plato was 28 when the old master died at the hands of a supreme court of 1000 members rotationally selected every few months on the mere basis of alphabetical rote from the roll of all the citizens. This event above all others (including the death of his "Tyrant" uncle Critias on the field of battle) is said to have solidified Plato's disdain of the loose nonprofessional style of Athenian democracy. After a prudent though self-imposed exile in which he traveled widely, Plato returned to Athens at age 40. It was at this time that he is said to have began writing various works designed to influence the general lay citizenry and to have founded the Academy of Athens.

Written in the style of "dialogues," Plato's numerous works are notable for their socially stratified views on Utopia; for their elitist advocacy of producing a professional ruling-class of philosophical politicians; and for their appeal to a theory of "abstract ideals" in their related account of knowledge. These works are often said to have contributed to psychology by anticipating later developments such as the introspective method (doctrine of recollection) and faculty psychology (by dividing the "soul" into reason, spirit, and appetite). Most notably, however, Plato not only proposed a third (rather idealist) version of the sensory emanation hypothesis (see our coverage of Aristotle who argued against it); but beyond even that was also one of the main ancient progenitors of the highly problematic "enrichment" theory of perception (where the "senses" and body are considered as hindrances to the ascertainment of "knowledge" which is only obtained through careful reasoning).

Plato's Republic, which outlines his views of human nature and the perfect (Utopian) state, was both antidemocratic and heavily influenced by Spartan ideology. The antidemocratic aspect is evidenced in the inequitable role he proposes for three classes of citizens in that state (the common people, the soldiers, and the "philosopher guardians"). The Spartan influence is evidenced in his advocacy of surreptitious selection of couples for mating, open weeding out of "sickly" young, and coeducation of girls and boys along rather bland non-artistic lines. The aim of the state is simply to provide victories in war against foes from city-states of roughly equal populations. The aim of education is to cultivate decorum in some and courage in the others for their eventual role in war. Furthermore, in Plato's Utopia, slaves would learn only the menial tasks required to serve the citizens.

In Plato's philosophical attempt to counter both the Presocratic materialists and the Sophists, he was deeply concerned with elaborating the difference between particular things (which are revealed by the senses) and ideals (the essence of things) revealed by reason. Plato argued that it is toward immutable "ideas" that the philosopher should turn to capture the true or ultimate realities because the world of mere sensible or perceptible things (material objects or events) is only a vague, transitory and untrustworthy copy of this ideal realm of existence.

In terms of ontology, therefore, Plato's position must be described as an "abstract" variety of objective idealism. It is objective because one can get at truth, but it is idealist and abstract because the route to truth was one of attaining an understanding of idealized "concepts" rather than concrete material things or events. For him, permanent, perfect, and changeless absolutes are more "real" than the perishable, transitory and imperfect objects we encounter in our everyday lives. Ideal conceptions have a timeless perfection which is never present in concrete transitory objects.

Furthermore, in contrast to former ontologically materialist positions which can be distinguished along "monist versus pluralist" lines, Plato's idealist account is neither monist nor pluralist. Instead, it is a our first clear exemplar of a dualistic ontology. His distinct "matter-idea" dualism is a profoundly influential progenitor of a later sort of dualism which is important for psychology and expresses itself as one between body and mind. Two central methodological points in this regard should be highlighted. First, whenever we encounter a mind-body dualism in later figures (e.g., Descartes), we should appreciate that it has its direct ancestor in the idea-matter dualism of Plato. Second, all such mind-body dualisms ultimately rely on an idealist metaphysic where mind is considered as primary and matter (or body) somehow derivative and secondary. This too has its origin in Plato. So, when considering Plato's metaphysic we want to appreciate this implied ontological aspect of his argument -regarding the priority or respective "reality" of the two parts of his dualism- along with the more explicit epistemological intention of Plato's position regarding "access" to these supposedly separate realms.

Matter and idea (mind) for Plato are not just analytically distinguishable, they exist separately and inhabit different ontological "realms." In order to illustrate the epistemological role of the philosopher guardian in sorting out the difference between the mere realm of sensible material appearance (of which "opinions" can be produced) and in gaining access to the higher realm of ideal reason or understanding (from which "knowledge" is gained), Plato's Republic employs the "Allegory of the Cave."

"Picture men dwelling in a sort of subterranean cavern with a long entrance open to the light on its entire width. Conceive them as having their legs and necks fettered from childhood, so that they remain in the same spot, able to look forward only, and prevented by the fetters from turning their heads. Picture further the light from a fire burning higher up and at a distance behind them, and between the fire and the prisoners and above them a road along which a low wall has been built, as the exhibitors of puppet shows have partitions before the men themselves, above which they show the puppets...

...See also, then, men carrying past the wall implements of all kinds that rise above the wall, and human images and shapes of animals as well, wrought in stone and wood and every material, some of these bearers presumably speaking and others silent...

...If then they were able to talk to one another, do you not think that they would suppose that in naming the things that they saw they were naming the passing objects? And if their prison had an echo from the wall opposite them, when one of the passers-by uttered a sound, do you think that they would suppose anything else than the passing shadow to be the speaker?...

...Then in every way such prisoners would deem reality to be nothing else than the shadows of the artificial objects...

...Consider, then, what would be the manner of the release and healing from these bonds and this folly if in the course of nature something of this sort should happen

to them. When one was freed from his fetters and compelled to stand up suddenly and turn his head around and walk and to lift up his eyes to the light, and in doing all this felt pain and, because of the dazzle and glitter of the light, was unable to discern the objects whose shadows he formerly saw, what do you suppose would be his answer if someone told him that what he had seen before was all a cheat and an illusion, but that now, being nearer to reality and turned toward more real things, he saw more truly?" (Plato's Republic, VII, 514a-515d, Paul Shorey’s translation).

By utilizing this allegory, Plato is suggesting that what ordinary folk take to be reality is not reality at all, but rather the distorted "shadows" of reality. What's more, ordinary men will have great difficulty recognizing this and would rather keep it that way.

But consider the two main methodological implications of this version of metaphysics. First, what has happened to motion and change? They have been relegated to the realm of base matter and the apparent. In contrast, the ideal realm, being "perfect" is necessarily immutable and static. Second, perception can no longer be the source of true knowledge since it is confined to the scope of shadows and illusion. For Plato, and for a millennia of monastic "Neoplatonists" thereafter, true knowledge can not be obtained through practice or experiment with regard to our natural surroundings, it can come only from some kind of philosophically contemplative exercise.

Regarding Plato's overall account, Bertrand Russell points out that there is an overemphasis on the "logical opposition" between the world of (ideal) essence and of transient sensible things, as well as an underemphasis on the "relative relations" between those concerns. Some of these shortcomings would be righted in the works of Aristotle on logic, physics, cause, and "sensitive" psyche (as outlined below), but it was Plato's metaphysical position that was best known and most often adopted in subsequent philosophy right up to the Renaissance and Reformation periods. As for psychology, in particular, subsequent theory in the areas of perception, personality, and especially in the subdiscipline of so-called intelligence testing remained very "Platonic" indeed right up to the later part of the 20th century (see Sections 2-5 in this regard).

Plato's perfect state, it should be added, was never attempted in any Ancient Greek polis nor was it wholly actualized in any other earthly republic or secular principality thereafter. Durant (1933), however, makes a convincing case for the profound influence and uptake of certain prominent features of Plato's Utopia into the organization, dogma and effectiveness of "the" Medieval Church in Europe:

"... For a thousand years Europe was ruled by an order of guardians considerably like that which was visioned by our philosopher. During the Middle Ages it was customary to classify the population of Christendom into laboratores (workers), bellatores (soldiers), and oratores (clergy). The last group, though small in number, monopolized the instruments and opportunities of culture, and ruled with almost unlimited sway half of the most powerful continent on the globe. The clergy, like Plato's guardians, were placed in authority... by their talent as shown in ecclesiastical studies and administration, by their disposition to a life of meditation and simplicity, and ... by the influence of their relatives with the powers of state and church. In the latter half of the period in which they ruled [800 AD onwards], the clergy were as free from family cares as even Plato could desire [for such guardians]... [Clerical] Celibacy was part of the psychological structure of the the power of the clergy; for on the one hand they were unimpeded by the narrowing egoism of the family, and on the other their apparent superiority to the call of the flesh added to the awe in which lay sinners held them....

Much of the politics of Catholicism was derived from Plato's 'royal lies,' or influence by them: the ideas of heaven, purgatory, and hell, in their medieval form, are traceable to the last book of the Republic; [Epilogue of Book X]; the cosmology of scholasticism comes largely from the Timaeus; the [contemporaneous] doctrine of realism (the objective reality of general ideas) [as contrasted with nominalism,] was an interpretation of the doctrine of Ideas; even the educational 'quadrivium' (arithmetic, geometry, astronomy and music) was modeled on the curriculum outlined in Plato. With this body of doctrine the people of Europe were ruled with hardly any resort to force; and they... contributed plentiful material support to their rulers, and asked no voice in the government" (Durant, 1933, pp. 49-50).

Aristotle (384-322 BC)

Born at Stagira in Thrace (where his father was a physician to the Macedonian king), Aristotle was first educated by physicians until the age of 18 when he moved south to Athens for a 20 year stint at the Academy under Plato. After Plato's death, Aristotle traveled briefly and taught notable pupils such as the young Alexander-the-Great but then returned to Athens to found his own philosophical school (called the Lyceum). It is said that he wrote down most of his works in the latter twelve year period (335-323 BC) of his life.

In contrast to Plato, Aristotle was both a naturalist and a thoroughly logical thinker who attempted to not only systematize his varied philosophical writings into a single overarching account (i.e., his Metaphysics) but to also present his other works (e.g., his Physics) in a careful, pedantic, consistent, and step-by-step professorial style. Some of these works were definitively naturalistic (e.g., those on the classification and movements of animals). Others were either distinctly psychological (e.g., De Anima, De Sensu, and those covering memories and dreams) or developmental (e.g., his short tract on youth and aging). Still others were more logical, political, ethical, or cosmological in their concerns. Several of Aristotle's treatises were also subsequently grouped under the title Organon ["Instrument"] and regarded as comprising his main logical works (Categories; On Interpretation; Prior Analytics; Posterior Analytics; Topics; On Sophistical Refutations).

Aristotle is one of the most fascinating figures from this entire Ancient Greek period. I like the naturalistic strivings of Thales, Heraclitus, Democritus, and even Anaxagoras; and I don't intend to slight them in any way. It is indisputable, however, that Aristotle has also remained a potent source of inspiration and error for later generations. Although his system of philosophy strictly speaking (like Plato's) represents an objective idealism, Aristotle's thinking is much more conducive to a naturalistic and scientific account of the world. While Platonism encourages a monastic retreat from the world, Aristotle was far more interested in engaging the worldly events of nature. He also made successive attempts to establish an assumptive methodological basis for clear and "logical" human discourse about observable events, as well as for the carrying out of careful empirical or rational inquiry into their underlying explanatory "causes."

Before proceeding to the pertinent details of Aristotle's logical contributions, naturalism, views on cause, and psychology, our first task should be to establish that his overall philosophical approach was objective idealist -most specifically with respect to how it overlapped with that of Plato.

In Aristotle's Metaphysics, the Platonic dualism (of matter and ideals) is revised somewhat into an account of "matter" and "form." The most important revision that Aristotle introduced here (aside from changing the latter term) was to reduce the absoluteness of the assumed distinction. What got Parmenides, Zeno, Empedocles, and Plato into trouble was their absolutization of the philosophical issues they dealt with respectively. But with Aristotle, there is a notable backing-off from such extremes and the presentation of a more relational ontologically monist position.

This relational distinction between "matter" and "form" blends in well with another important analytical distinction Aristotle made between the "actual" and the "potential." Given that he posits a relation between actual manifestations of matter and their potential form (or "essence"), it is easy to appreciate that these are understood by Aristotle to exist in some sort of monistic unity with each other. Aristotle's account was not 100 percent in this regard, however, for he did also posit some exceptional forms which do not have "actuality" in matter (e.g., the Aristotelian "God" and one aspect of his account of Soul) but it is clear that he did manage to back off considerably from the absolute duality of ontological realms posited by Plato for matter (on the one hand) and ideas (on the other).

For Aristotle, all matter is actualized form and yet also holds other form potentials within it. Similarly, most (but not all) form is actualized in particular instances of matter or functions of matter. There tends to be a kind of assumed unity between the two which we don't see in Plato's account. Marble, for instance, is matter to the "statue" and the statue is form realized in marble or "bronze". The word realized, however, is important because like in Plato, the "form" (by virtue of its definition as a "potential") is -at least in one sense of the term (Book V, Part 11)- suggested to exist "prior" to -or is otherwise "more real" than (Book VII, Part 3)- the actualized material statue. In other words, the "form" of any perceptually given (particular) object is taken by Aristotle to be its essence. Aristotle's position is that the form of the statue -the potential for its material substance to become an actualized end state (though not the statue's "shape")- is already there in the block of "stone." The active efforts of the sculptor merely reveals that form -e.g., as an actualized statue of "Hermes" (Book III, Part 5). Such form "potency" is preexisting, eternal and "unchangeable" (Book V, Part 12) -just like in Plato- and may or may not become realized or revealed in particular manifestations of matter. Particular ("concrete") objects -even those worked on by the highly skilled artisan- may approach or approximate the perfection of the forms existing within, but they do not ever attain such potential perfection.

When Plato discusses the distinction between particular objects and ideals, they are clearly being conceived as existing in different ontological "realms" (localities), but for Aristotle they are not. For him, forms are substantialized (embodied within matter) while the "universals" of Plato are not. Aristotle's position implies a very complex interweaving of the two so that they produce an ultimate unity. The forms have a prior existence of their own but just not in a different place. They exist within the material substance or living body (organism) as a potential:

"Again, 'being' and 'that which is' mean that some of the things we have mentioned 'are' potentially, others in complete reality. For we say both ... of that which can actualize its knowledge and of that which is actualizing it, that it knows... And similarly in the case of substances; we say the Hermes is in the stone, and the half of the line is in the line, and we say of that which is not yet ripe that it is corn..." (Book V, Part 7).

"And when we have the whole, such and such a form in this flesh and in these bones, this is Callias or Socrates; and they are different in virtue of their matter (for that is different), but the same in form; for their form is indivisible" (Book VII, Part 8).

"For even if the line when divided passes away into its halves, or the man into bones and musclesand flesh, it does not follow that they are composed of these as parts of their essence, but rather as matter; and these are parts of the concrete thing, but not also of the form..." (Book VII, Part 10).

Much of this is a clear improvement over Plato and appears to flirt (at times) with a return to some sort of dynamic Heraclitean materialism. Russell (1946) cautions us, however, that although a "form" (for Aristotle) is intended as something quite different than a Platonic universal ideal, it does have many of the same characteristics: "Form is, we are told, more real than matter; this is [at least] reminiscent of the sole reality of the [Platonic] ideas" (p. 179). Russell then quotes Eduard Zeller (who we can simply paraphrase) by saying that Aristotle had: "only half emancipated himself from Plato's tendency to hypostatize [(reify)] ideas. The 'Forms' had for him, as the 'Ideas' had for Plato a metaphysical [(assumed ontological)] existence of their own... And .... [are at times treated as if they had the status of] .... an immediate presentment of a supersensible world, ... [which (as such) is accessible only by way of] .... intellectual intuition" (After Zeller, 1897, in Russell, 1946, p. 179).

To put this point a little more plainly, the fact is that Aristotle's (idealist) version of relational monist ontology is but a mere methodological half-step out of Plato's absolute idealist and ontologically dualist tradition. This can be appreciated when we note the remaining uneven relationship between actualized matter and its supposed underlying (resident) form potential. Aristotle usually talks about matter striving to be realized in form and form being substantiated in matter. This is certainly a recognition that movement, motion, change, or development occurs but we should be careful to notice where that motion (change or development) is located: It is in the matter, not in the form. For Aristotle, "sensible substance" changes but only so as to approximate the presumably "unchanging," immutable, and "indivisible" form existing within it (Book XII, Parts 2, 7 & 8). Once again, the idealized "forms" are assumed to have a timeless perfection which is never quite attained by "concrete" transitory objects.

When it comes to his postulation of such albeit substantialized forms, therefore, Aristotle's idealist (though relational) ontological monism contrasts unfavorably with the simpler (more parsimonious) materialist monism of Heraclitus and Democritus. This may seem like a subtle or minor contrast but it actually makes a world of difference. It means that when we get the Classical period of Greek philosophy (specifically Plato and Aristotle) what are now being taken as the prior, more real, or fundamental constituents of the universe -the ideals or forms- are assumed to be static and unchanging entities which exist either in their own realm (Plato) or embedded within their particular material manifestations (Aristotle).

Aside from these questionable, equivocal, and problematic idealist aspects of his philosophical system, Aristotle did make many other more long-lasting logical and methodological contributions to posterity. So let's move on to cover those contributions. Most notable among these are: his initial introduction of deductive "syllogism" to the analytical lexicon of philosophy (Prior Analytics); his proposal (elsewhere) of three maxims of so-called formal (deductive) "logic"; and his very useful doctrine of "four" causes (reasons for) which subsequent scientific practice would utilize to varying degrees and with varying success.

A "syllogism" is simply a trio of propositions of which the latter (the conclusion) follows from granting the truth of the other two (the major and minor premises). As a methodological thinker, Aristotle noticed that when presented with a three-part syllogism (such as: Socrates is a man, all men are mortal, therefore Socrates is mortal), certain regularities or truisms have to be assumed about the categories (nouns and predicates) contained in each of the three propositions. He therefore

made a concerted subsequent effort to formalize the rules of logic as they had developed implicitly in those who preceded him (mainly Parmenides and Protagoras). These truisms have come to be called Aristotle's three maxims (or laws) of logical discourse.

The three maxims of what would later be called "formal logic" -which Aristotle somewhat implicitly set down in his Metaphysics and Posterior Analytics- can be described as follows: (1) Law of Identity: A is A; (2) Law of Noncontradiction: A is not non-A; and (3) Law of Excluded Middle: Any X is either A or non-A. In our example, the maxims would simply state respectively that: (1) Socrates is always Socrates; (2) Socrates can not be equal to that which is not Socrates; and (3) There is nothing other than Socrates and not Socrates.

As you can probably appreciate, these maxims are statements about the necessary conditions that exist for the descriptive categories used while entering into ontological arguments. In other words, they relate to (emphasize or highlight) the necessarily assumed consistency between the nouns or predicates utilized in the various propositions of such arguments. They are maxims or laws of clear discourse which may or may not apply to particular cases of actual (concrete) being as such.

Aristotle's exposition of these logical laws of correct "thinking" was certainly a groundbreaking advance over his predecessor's loose art of argumentative discourse. Russell states for instance:

"Aristotle's influence, which was very great in many different fields, was greatest of all in logic. In late antiquity, when Plato was still supreme in metaphysics [(primarily on issues of epistemology)], Aristotle was the recognized authority in logic, and he retained this position throughout the Middle Ages" (Russell, 1946, p. 206).

It should be pointed out, however, that the considerable limitations of Aristotelian logic (its overemphasis on deduction and its abstract either/or quality) were direct echoes of the idealist legacy passed down from Socrates and Plato to Aristotle. His three maxims of Identity, Noncontradiction and Excluded Middle are certainly helpful in promoting clear discourse (defining one's terms and drawing deductive inference). The problem with them arises when one begins to overgeneralize them; to treat them as rules that necessarily apply to being (the nature of things).

For instance, consider the formal logical contrast between "life" and "non-life." This latter non-life category is an abstract negation of life -i.e., everything that is not alive (rocks, machinery, etc.)- and as long as we are dealing with oppositions like this, all three maxims (including the noncontradiction law) always hold. Yet consider now, the more ontological or naturalistic contrast between "life" and "death" (which is the concrete negation of that which was once alive). If as a biologist, I want to know about the nature of life (living organisms) I can not understand that topic without studying death because life and death are (just as Thales and Heraclitus suggested) so intimately or dialectically related that the essence of one depends on the other. Organisms which are living from day to day are also dying from day to day. Such basic vital processes are always two-sided -i.e., they are a constant "building and destroying" as Heraclitus once put it. So, if we are trying to grasp such naturalistically related processes as life and death, the kinds of points which Heraclitus is making seem to apply, because being is contradictory. The noncontradiction maxim of Aristotle does not apply in this particular concrete instance of being.

Although this important distinction between discourse and being was (in the main) handled quite well by Aristotle, it was not well handled by later 17th-18th century mechanical thinkers (covered in Section 2) who ran into great difficulties in accounting for motion, change, and development because those topics imply an

understanding of objective rather than logical contradiction in nature. Nature is contradictory in a way that is not necessarily reflected in the realm of exclusionary (either/or) symbolic discourse.

This is all quite ironic because we can recognize in Aristotle's writing (choose any one at random) some of the lingering dynamics of the Presocratic period being reasserted. He was constantly utilizing terms like the coming to be and the passing away because his notion of substance (matter) was that which changes (Physics, Book I, Part 2, Part 7, Part 8). Yet when we get to the 17th century we'll find they utilize a markedly more static notion of material substance as that which persists through change.

Historically, such overgeneralization worked to set our inquiries back in a way that Aristotle would not have liked. He wanted to understand motion, change, and process in both physical matter and in developing organisms. What we can say about the later mechanistic thinkers is that they granted a changing universe and even worked successively (e.g., from Galileo, 1590 through to Newton, 1686) toward a theory of mechanical motion but had no theory or adequate account of change or development in the organic or organismic realm of natural processes. These limitations of the way Aristotelian logic (etc.) were picked up and utilized by later philosophers, however, were not drawn out into the open until the 19th century in the equally groundbreaking exposition of dialectical logic by Hegel, Marx, and Engels.

An altogether more favorable analysis (even from the perspective of the relative present) can be made of Aristotle's somewhat more explicit outline of four causes (Formal, Material, Efficient, and Final). Although he didn't always apply them consistently, Aristotle's Metaphysics (Book I, Part 3; Book V, Part 2) and Posterior Analytics (Book II, Part 11) did point out the "four" kinds of information we need in order to understand any object, process, or action we may have under study: 'What is it; from what does it come; by what agent; and for what end?'

"Evidently we have to acquire knowledge of the original causes (for we say we know each thing only when we think we recognize its first cause), and causes are spoken of in four senses. In one of these we mean the... the essence (for the 'why' is reducible... to the definition [the Formal cause]...); in another the matter or substratum [(Material cause)], in a third the source of the change [(Efficient cause)], and in a fourth the cause opposed to this, the purpose and the good (for this is the end [-the Final cause-] of all generation and change)" (Metaphysics, Book I, Part 3).

"We think we have scientific knowledge when we know the cause, and there are four causes: (1) the definable form, (2) an antecedent which necessitates a consequent [(Material cause)], (3) the efficient cause, (4) the final cause" (Posterior Analytics, Book II, Part 11).

"Besides this it is plain that when the causes are being looked for, either all four must be sought thus or they must be sought in one of these four ways" (Metaphysics, Book I, Part 8).

From the standpoint of science, the inductive aspects and explanatory potential of Aristotle's "causes" (reasons "why") go well beyond the confines of the categorical either/or deductive logic passed down to him from Plato (see Randall, 1960). Most notably, there is an ever-present methodological tension in Aristotle's writing between his discursive logical laws (which seem to reject contradiction in nature), his occasional reference to an "unmoved" prime mover (which seems to play the role of an initial efficient cause for motion in the cosmos), and his allowance for all "four" kinds of cause. Why? Because the seeking out of answers to the "final cause" ('for what end') question seems to imply an intimate understanding of physical

objects, events, or organisms in their respective forward-reaching and teleological relations (i.e., as contradictory and inherently dynamic processes of nature).

For instance, Aristotle's reasons why allow for not only discussion or formal definitional classification of what animals look like -their categorical appearance- (how many legs, etc.); but also for informed inductive speculation about deeper (more essential) questions like how each of these varied apparent groupings (the observable As and non-As) might have come to be that way; or how they may each form part of wider -less apparent- groupings (Man, Mammals, etc.), as well as how they might all fit together into a scala natura. This "scale [or ladder] of nature" itself, in turn, poses further relational and causal questions about the ecology of animals and their actual or potential developmental contradictions.

Aristotle's scala natura (a.k.a., ladder or chain of being) consisted of God, man, mammals, oviparous organisms with perfect eggs (e.g., birds), oviparous organisms with non-perfect eggs (e.g., fish), insects, plants, and non-living (inanimate) matter. He considered each link in the chain as a "species" of being. In our terms, however, he made extensive taxonomic studies of more than 500 animal species -dissecting many of them (with the exception of man). The observations he published in Generation of Animals and Historia Animalum (Investigation of Animals) were meticulous, and his differential classification scheme was conspicuously modern because it departed from the prior Greek practice of using merely apparent categories such as with feet vs. footless and winged vs. wingless (Balme, 1975).

The ongoing dominance of mere categorical (either/or) logical thought, however, seems to have played a large part in the fact that three of the "four" causes which Aristotle utilized were subsequently rejected or rather ignored by 17th-18th century mechanistic thinkers -who favored appeal to "efficient" (by what agent) cause in their mechanical "billiard-ball" explanation of inclined planes, reflex action, and even human will (Section 2). Similarly, even after the establishment of psychology as a distinct discipline (1879 onward), the rest of the causes only appeared definitively with the American functionalist movement of the 1890s (Section 4) and have waxed and waned rather irregularly in the varied schools or systems of psychology ever since that time (White, 1990, pp. 3-4; C.W. Tolman, 1983a&b, 1991d).

Aristotle's coverage of what would now be considered psychological topics is found primarily in his overarching De Anima [On the Soul] and a more specialized tract "De Sensu et Sensibili" [On Sense and the Sensible]; as well as in two lesser tracts called: De Memoria et Reminiscentia [On Memory and Reminiscence] and De Somniis [On Dreams]. Each in their own way reflect both his naturalistic approach to the world and the idealist aspects of his philosophy.

With De Anima, Aristotle became the first Greek philosopher to devote an entire separate work to the psychological topics of sensation; reminiscence or imagination

(now called memory or mental imagery); and reason or thought (now called higher mental processes or cognition). Book I of that three-book work starts out with a critical review of the sketchy and sometimes transparently arcane views of Aristotle's predecessors on such topics (stretching from Thales through to Plato).

Basically, Aristotle argues that if "psuchê" (an ancient Greek word equivalent to "psyche" but which is usually translated most problematically as "the soul") is a distinctive "principle", characteristic, or aspect of "active" and "living" organisms -rather than either a kind of "element" or mixed "harmony" of "spatial" substance (as the materialist traditions held) on the one hand; or a disembodied "incorporeal" entity (as the mystical traditions held) on the other- then the most "appropriate" way to investigate its various manifestations (in plants, animals, and human beings) is a "natural[istic]" one (see Book I, Part 1, 4 & 5). More precisely, what Aristotle suggests in terms of procedure is that we should start with a generalized descriptive encapsulation (a "summa general" indicative of these as yet ill-defined or varied processes); and then move carefully forward from such early "conjecture" to "investigate" each such "form of soul" so as to successively refine our initial understanding of their "essential nature" and ultimately "discover the derived [functional] properties" of each (see Book I, Part 1; Book II, Part 1 & 4).

Aristotle's critical introductory comments about the proper assumptive basis or procedural starting-point for the analysis of such a new "subject" area are for the most part followed up quite well and elaborated with details throughout Book II and III. At the outset of Book II a provisional "general formula applicable to all kinds of soul," is presented which "describes" (but does not define) psyche in abstract (non-particular) terms "as the first grade of actuality of a natural [living] organized body" (Book II, Part 1). This is Aristotle's initial generalized answer to the ontological "What is it [that we are setting out to study]?" question he had raised in the first three paragraphs of De Anima. For as he says upfront:

"Further, does soul [psyche] belong to the class of potential existents, or is it not rather an actuality? Our answer to this question is of the greatest importance" (Book I, Part 1).

Having now indicated that psyche is an as yet ill-defined "actuality" which must therefore be investigated further, Aristotle then proceeds to fill in the more concrete details -i.e., the "particulars subsumed under the [above] common name." That is, he begins to distinguish the various manifestations of psyche in more precise terms of the particular functional utility or activities they each respectively carry out. Aristotle argues that in plants psyche fulfills an "active" but merely "nutritive" and "reproductive" function only; but in animals it can be observed to have become a "sensitive" (sensory or perceptive) and "locomotive" power with characteristically derivative though "sentient" and directional "means to ends" relationships ("since Nature does nothing in vain"); while in human beings it is (as well) the capacity for both "particular" intentionally goal-oriented "practical" reasoning and higher (more "universal") "intellective" ("theoretical" or "speculative") thinking (Book II, Part 1-5; Book III).

"That perceiving and practical thinking are not identical is therefore obvious; for the former is universal in the animal world, the latter is found in only a small division of it. Further, speculative thinking is also distinct from perceiving -I mean that in which we find rightness and wrongness- rightness in prudence, knowledge, true opinion, wrongness in their opposites; for perception of the special objects of sense is always free from error, and is found in all animals, while it is possible to think falsely as well as truly, and thought is found only where there is discourse of reason as well as sensibility" (Book III, Part 3).

In providing this detailed, broad-spectrum, and functional account of various forms of psychic activities, Aristotle can be recognized as explicitly distancing himself from the prior Platonic view which merely assumed the "soul" to be devisable into "parts" which reside (as abstract and ill-defined potentialities or even spiritual entities) in various locales of the human body -e.g., thought in the head, courage in the chest, or appetite in the abdomen. We must be ever careful, however, not to overstate the case for Aristotle's functionalism.

There are two intimately related reasons for caution that can be mentioned with regard to his account of psychological topics in De Anima. First of all, there is the relatively minor point that, in Book I, Aristotle often continues to utilize the older language of the Democritean "substantial" theory of mental activity even while explicitly attempting to break free from it -toward what is best described as a near functionalist account peppered with hints of his idealist (form-matter) ontology. Secondly, a more serious (major) point is that the idealist aspect of Aristotle's ontology itself actually stands in the way of a thoroughgoing or completely functionalist account of psychological processes. Noting this second obstacle here and now will be especially useful to us later because we'll encounter it in subsequent figures as well.

To help illustrate these two related points, I've selected a few crucial passages from Book I for our joint consideration. In the first paragraph of the following extract, for instance, Aristotle is attempting to articulate the rather subtle difference between erroneously assuming the lower manifestations of psyche to be 'material or spatially located entities' versus assuming them to be 'special functional activities' of the living substantial "vehicle in which" (or by which) those functions are carried out. In the initial paragraph, Aristotle seems to do this quite well and it is clear that he is calling for a bi-directional functional analysis of basic (lower) psychological processes in both their apparently passive "sensory" (outside-inwards) and more active "movement" producing (inside-outwards) roles. But, in the subsequent paragraph dealing specifically with "mind" ("nous" -by which Aristotle seems to mean the more complex, uppermost, or highest reaches of human reasoning ability and mental capacity), he slips rather abruptly back into his quintessentially idealist (form-matter) ontology -where the human "mind" is again likened to a Platonic "impassive" or "divine" eternal entity.

".... For example we may regard anger or fear as such and such movements of the heart, and thinking as such and such another movement of that organ, or of some other; .... (the special nature of the parts and the special modes of their changes being for our present purpose irrelevant). Yet to say that it is the soul [psyche] which is angry is as inexact as it would be to say that it is the soul that weaves webs or builds houses. It is doubtless better to avoid saying that the soul pities or learns or thinks and rather to say that it is the man who does this with his soul. What we mean is not that the movement is in the soul, but that sometimes it terminates in the soul and sometimes starts from it, sensation e.g. coming from without inwards, and reminiscence starting from the soul and terminating with the movements, actual or residual, in the sense organs.

The case of mind ["nous" -the higher 'form' of active intellect] is different; it seems to be an independent substance implanted within the [human] soul and to be incapable of being destroyed. If it could be destroyed at all, it would be under the blunting influence of old age. What really happens in respect of mind in old age is, however, exactly parallel to what happens in the case of the sense organs; if the old man could recover the proper kind of eye, he would see just as well as the young man. The incapacity of old age is due to an affection not of the soul but of its vehicle, as occurs in drunkenness or disease. Thus it is that in old age the activity of mind or intellectual apprehension declines only through the decay of some other inward part; mind itself is impassible. Thinking, loving, and hating are affections not of mind, but of that which has mind, so far as it has it. That is why, when this

vehicle decays, memory and love cease; they were activities not of mind [(as form)], but of the [material] composite which has perished; mind is, no doubt, something more divine and impassible" (Book I, Part 4).

So, as indicated immediately above, Aristotle's (form-matter) idealism -which we first encountered in his Metaphysics- is carried over into his psychological notion of a higher active "intellective soul" (a.k.a., "mind" or "nous") which unlike all lower manifestations of animal or human psyche (e.g., sensation, reminiscence, or even object-oriented "practical" reason) is not a material function of the body but is assumed by him to survive after death (see also De Anima, Book III, Part 4 & 5). Yet, now we have made these required caveats as plain as possible, I'd like to reemphasize that the more prominent tendency in Aristotle is to consider the other manifestations of psyche to be functional utilities of particular sorts of living bodies -or organs of a body- which can be classified according to the types of activity they carry out.

This carefully qualified case for Aristotle's functional approach to psychological topics can be made by considering how his causal (outside-inward) theory of sensation (in general), and his theory of visual perception (in particular), departed from three prior versions of the so-called emanation hypothesis put forward by Empedocles, Democritus, and Plato (see De Anima, Book II, Part 6-12; and "De Sensu").

Empedocles Emanation hypothesis: Lantern simile

unidirectional (inside-outward)

Democritus Emanation hypothesis: Image theory

unidirectional (outside-inward)

Plato Emanation hypothesis: Synaugeia theory

bi-directional (inside-outward-inward)

Aristotle Discriminative Act account: Pneuma theory

unidirectional (outside-inward)

The first sketchy attempts to produce a theory of vision emphasized the respective roles of material elements assumed to be contained within the eye (predominantly water and fire). The water, was said to be a passive though reflective element similar to a mirror -which accounts for observable reflections on the surface of the eye (as seen by one person gazing closely into the eyes of another). Fire, on the other hand, was said to be a more active element.

For example, Empedocles suggested that fire in the eye is sent outward (emanated) to objects just as a lantern lights a roadway. The exact details of his account have been lost to posterity and what we do know about it comes only from those who argued for or against his views. We do not know, for instance, whether the emanated fire is assumed to have reached the object and to have bounced back to the eye (like a sound bounces off a the flat face of a rocky bluff to return to us in the form of an echo). Yet in having proposed this lantern simile -which in and of itself is taken as an initial unidirectional (inside-outward) version of the emanation hypothesis- Empedocles seems to have assumed that there has to be some sort of physical contact between the object and the sensory organs if stimulation is to occur at all. The content and structure of those respective organs also seem to have been recognized as providing a specificity for the differences between the kinds of sensations produced or picked up. He is often said to have reasoned, therefore, that since all objects contain some proportion of each element (water, fire, earth, and air), the sensory organs act according to the principle of "like seeking like".

Democritus proposed a similar, though (outside-inward), version of the emanation hypothesis. He reasoned that since all material objects are "active" collections of

atoms, they must emanate streams of particles which reach other objects -some of which happen to be sensory organs. All such sensations are the product of some variety of contact of atoms with differentially substantive sensory organs. Inherently active material substance emits (emanates) structured streams of atoms into the surrounding medium (air or water) which can be picked up either through immediate physical contact (as in taste or touch) or contact at a distance (as in smell, hearing, or vision). The point is that since such sensory organs (just like all other material objects) vary with respect to their constituent elements, they may admit particles of only one particular (or predominant) kind. Thus, Democritus is said to have adhered to the now somewhat modified epistemological principle of "like through like".

For Democritus, it is the orderly combination of such "like" elements which somehow produces the vast array of palpable objects or observable events we deal with in our ordinary lives. The analytical hitch is that (in his ontological account of material substance itself), Democritus had already attributed hardness, weight, and solidity to atoms; while other qualities (smell, color, and temperature) were considered as existing only in "common opinion." In the case of sight, therefore, Democritus is said to have been forced into distinguishing between sensory vision and mental vision. In sensory vision, structured substances are (in the form of "flouting pictures") transferred directly onto the pupil and perhaps into the eye. These "images" are assumed by him to be an exact copy of the object's atomic structure, but colors are not. Colors where said to occur as an indirect (perhaps mental) consequence of the contact between atoms and the visual organ. There might be a definite arrangement of atoms which correspond to each color, but since colors do not reside in atoms themselves, these colors must somehow be imparted by us to the objects we see.

Anaxagoras (like Aristotle later on) is the odd man out in these early epistemological discussions. First of all, let's recall that it was Anaxagoras who distinguished between material substance and "nous" (a mental ordering principle which allows us to attend to the structured order, pattern, and sequential arrangement of the world around us). This ontological distinction between nous (mind) and the objects which are attended to, can be appreciated as an early attempt to emphasize an active though naturalistic account of what has come to be called the subject-object relation. The immediate implication is that every conceivable case of sensation is an active relation between a subject (which observes) and an object (which is observed).

As is often suggested, his immediate argumentative point may have been simply that mere passive (mechanical or physical) contact with an external object was, in itself, insufficient to guarantee the production of a sensory impression (or perception) in the subject. At the very least, a counteraction by the differentially sensitive sensory organ (which is itself an active collection of conflicting elements) was also needed. Yet when this point is pushed just a little bit further, it becomes apparent this is the first indication that not only the activity of the sensory organ, but also the movement of the eyes, the turning of the head, and even the organism's goal-directed locomotion through space must be somehow drawn into our account of vision or any other sensory modality.

Furthermore, Anaxagoras seems to have had no trouble at all with what would later be called the problem of "secondary qualities" (see Section 2). This is because (unlike Democritus), Anaxagoras assumed the traditional opposites or qualities (hot and cold, wet and dry, and also "color") to reside within the elements (or "seeds") and -by extension- within the objects of perception themselves. The perception of color, therefore, presented no special epistemological problem for him as it had for Democritus and a host of subsequent thinkers.

His overall account of the subject-object relation is often summed up in a few pithy phrases which contrast with that of Empedocles, Democritus, and -as we will soon see- with Plato. For instance, in having recognized the ontological difference (as well as the epistemological unity) between "nous" (the organism's mindful activity) and the "objects" being observed or attended to, he is said to have adhered to a principle of "unlike to unlike" in his account of our contact with the world around us. In other words, Anaxagoras realized that even though the subject and the object are analytically different they also form a unity through their active reciprocal relationship. The subject and the object (just like the elements themselves) are in no way "cut off" from one another as if by a "hatchet."

The analytical gains made by Anaxagoras on the subject-object relation, were not picked up by Plato. In the Timaeus, Plato passes down to posterity a rather retrograde 'synaugeia' (union of rays) theory of vision and color which is similar in many respects to the initial emanation hypothesis of Empedocles. Fire in the eye, he suggests, proceeds outwards and when that "inner fire" reaches an object it is seen (Part 13). Plato never, however, quite gets around to telling us exactly how this might occur. Instead, he merely alludes to the as yet ill-defined but seemingly joint concepts of both a "line of vision" (which presumably has something to do with the direction of the head or eyes) and of some sort of physical "coalescent" (or proximity) between the outward "stream of vision" and the "light of day":

"When the light of day surrounds the [outward] stream of vision, then like falls upon like, and they coalesce, and one body is formed by natural affinity in the line of vision, wherever the light that falls from within meets with an external object" (Plato, Timaeus, Part 13).

Similarly, whenever that outgoing "visual ray" encounters (and is "dilated" by) light travelling in the "opposite direction" -presumably from the mildly reflective surfaces of objects- various "colors" are also seen (Part 36). Thus, in Plato's bi-directional version of the emanation hypothesis the eye and object are assumed to be somehow connected according to this revised union of rays notion of "like to like" and colors are produced as a physical interaction between outgoing and incoming rays of light.

These were the four sketchy versions of visual sensation or perception theory which Aristotle had to contend with while working out his own position in De Anima. In accordance with his initial goal of taking up what is "sound" in previous accounts, Aristotle borrows sparingly and makes notable improvements on them all. To his credit, Aristotle presents a unidirectional (outside-inward) account of sensation which (as we noted above) is itself located within a more wide-ranging (qualitative and quantitative) continuum of psychic activities. The sensory function was considered by him to be similar to the vegetative function (common to plants or animals) in that they both take in or "assimilate" the external object yet also different from it because while the vegetative function entails taking over the "substance and the form" of the external object, sensation receives "only its form":

"By a 'sense' is meant what has the power of receiving into itself the sensible forms of things without the matter. This must be conceived of as taking place in the way in which a piece of wax takes on the impress of a signet-ring without the iron or gold..." (De Anima, Book II, Part 12).

To account for exactly how transmission of the form of an object without its matter is possible, Aristotle emphasizes the importance of intermediary though "transparent" agents (mediums) between the object and the sense organ. Even touch (which seemingly involves the direct physical contact between the object and the organism) is recognized as involving a "medium" of the "flesh" (skin) between object and the sensory organ (which resides somewhere "deeper" within the body).

Despite the somewhat archaic physiology assumed, Aristotle's overall account of the five senses is functional because both the conditions of adequate stimulation and the discriminative act are considered. His "discriminative" act account of sensation rejects all three of the previous versions of the "emanation" hypothesis and yet at the same time retains the gains made by Anaxagoras regarding the veridicality of the subject-object relationship (see also "De Sensu," Section 1, Part 2-3).

In the case of vision, for instance, the causal-ontological processes he lays out (in De Anima and "De Sensu") begins with the object (which reflects light to varying degrees) and proceeds somewhat mechanically inward through the roughly transparent medium (of air or water) to the eyes, veins, and heart (his assumed seat of all sensation). The structured light does not physically enter the body but merely stimulates the sense organ (the eyes) into activity and this activity is somehow "carried" along with the blood to the heart. The issue of appropriate conditions for the act of looking, however, are not overlooked by Aristotle. Furthermore, he also concurs with Anaxagoras on the issue of color perception (see especially "De Sensu," Section 1, Part 3 -which presents his theory of color as "residing in" objects and the mediums rather than "juxtaposed" or "superimposed" onto them).

De Anima itself even introduces the new concept of "common sensibles" as a way to describe or indicate how various aspects of a given object might be picked up by the active organism:

"Each sense has one kind of object which it discerns, and never errs in reporting that what is before it is colour or sound (though it may err as to what it is that is coloured or where that is, or what it is that is sounding or where that is). Such objects are what we propose to call the special objects of this or that sense.

'Common sensibles' are movement, rest, number, figure, magnitude; these are not peculiar to any one sense, but are common to all. There are at any rate certain kinds of movement which are perceptible both by touch and by sight" (De Anima, Book II, Part 6).

"Each sense then is relative to its particular group of sensible qualities: it is found in a sense-organ as such and discriminates the differences which exist within that group; e.g. sight discriminates white and black, taste sweet and bitter, and so in all cases. Since we also discriminate white from sweet, and indeed each sensible quality from every other, with what do we perceive that they are different? It must be by sense; for what is before us is sensible objects" (De Anima, Book III, Part 2).

The following set of quotations (from George Sidney Brett) provide a useful taste of the significant gains made by Aristotle on many of these epistemological issues. The middle quotation, however, mentions the concept of "pneuma" which might be surprising for anyone familiar with the exact text of De Anima. I believe it is more proper to suggest that this concept came to be appended to Aristotle's views by the early (materialist leaning) Stoic philosophers, but we many not ever be sure on this point because while Aristotle is known to have produced some 170 odd works only 47 survive. Anyway, while discussing (jointly) the content of Aristotle's De Anima and "De Sensu", Brett put these points as follows:

"Looking back on this theory we see how much progress has been made. The idea of a fire [emanating outward] from the eye [(Empedocles, Plato)] is rejected. Plato had been compelled to explain our inability to see in the dark as due to the extinction of this fire by the darkness, which Aristotle condemns as nonsense. The image on the pupil [-which Democritus had emphasized in his (outside-inward) flouting-image theory-] is now clearly recognized as only one case of reflection,

analogous to that in a mirror and Aristotle realizes that if the image is the cause of vision there is no reason why... [a] mirror should not see. On the other hand, the idea of Democritus that colour is purely subjective is corrected by making it [more] dependent upon the object both for its production and its definite character" (Brett, in Peters, 1953, p. 103).

"The most interesting ... [aspect] of Aristotle's theory is the use of pneuma in all sense-experience. [Such pneuma is said to be a sort of bodily secretion contained in the sense-organs which is extruded into the bloodstream when those sense-organs are stimulated by changes in the surrounding medium (air, water, or flesh).] The organs of sense are in every case constructed to propagate the outer movements [(of the respective external mediums which carry structured information from objects to the sense organs)] inward to the pneuma which they contain; this movement results in a further movement which the pneuma transmits through the blood to the centre the heart [(Aristotle's assumed seat of sensation)]. The... [bodily] pneuma is ... acting as the universal [internal] medium of sensation. In later psychology this appears as a doctrine of 'animal spirits'" (Brett, in Peters, 1953, p. 105).

"The value of this definition of sense in terms of function is very great. It breaks away from those early ideas of transmission of [material] particles [into the substantive mind (Democritus)]...: it succeeds in showing the significance of [ongoing and appropriate discriminative] contact as the condition of sensation; and it settles the [ancient] question whether perception demands a relation of like to like [(Empedocles, Democritus)] or unlike to unlike [(Anaxagoras)]. The object is always unlike the sense-organ; its reality as perceptible consists in its power of affecting the organ... it arouses an activity of the organ and as that is the sensation, the object [its structured form but not its substance] is assimilated by the organ in the [organism's discriminative] act of sensation. An object that does not admit of this assimilation cannot be perceived: it is like food that cannot be digested" (Brett, in Peters, 1953, p. 106).

In contrast to Plato, who distrusted both sensation and perception as sources of veridical knowledge, Aristotle embraced them both (not only as the immediate source of our initial understanding of our surroundings but as an important procedural starting-point for further "scientific" investigation). To explain anything for Plato was to pierce by way of intellectual reason or intuition the veil of mere sensory or perceptual appearance (which shrouds ideal patterns). For Aristotle sensation "never errs" and even though a particular aspect of (or judgment about) a given act of perception might be in error (e.g., the actual direction or the exact source of a given sound) it is easily corrected by collecting more and better information -actively seeking out the knowledge we require over time and under better conditions. It is in this goal-directed and forward reaching way that we further refine or deepen our initial understanding and ultimately get at the essence of whatever object, event, or process we might have under study. For Aristotle, it wasn't sufficient for "one who is actually a man of science" to sit down and think. One has to also make further active observations and discoveries so as to sort out the essential properties of an object, event, or process from its incidental or "accidental" ones.

A similar case for Aristotle's functional approach can be made with regard to how his account of ethical deportment differs from that of Socrates. For Socrates, mere awareness of what is good, is assumed to compel a reasonable person to follow the virtuous life. Aristotle, however, moved well beyond such lofty Socratic platitudes or interpersonal expectations by putting forward a more situationally dependent and roughly pragmatic approach to human ethics. First of all, in Nicomachean Ethics (Book II) he implies that for every emotionally arousing actual situation there is a definite correct optimum affect (a potential ethical reaction linked with an appropriate "action" or form of "conduct" which is either actualized or not). Mere

awareness (or even intellectualized knowledge) of the optimum affect or conduct for that situation can not -in and of itself- make a person act virtuously. For that, some sort of deliberative "exercise" of "character" (motivated by "practical" reason and "wisdom") is required. Ethical conduct always requires an actualized "choice" between various potentially available "qualities" or "states of character".

"The qualities of character can [according to Aristotle] be arranged in triads, in each of which the first and last qualities will be extremes and vices, and the middle... a virtue... So between cowardice and rashness is courage; between stinginess and extravagance is liberality; between sloth and greed is ambition; between humility and pride is modesty... between moroseness and buffoonery, good humor; between quarrelsomeness and flattery, friendship; between Hamlet's indecisiveness and Quixote's impulsiveness is self-control" (Durant, 1933, p. 86).

This recognition of the "practical" working relationship between virtuous "actions" and their required deliberative "choice" of optimum character qualities has come to be called Aristotle's doctrine of the golden mean:

"Virtue, then, is a state of character concerned with choice, lying in a mean, i.e. the mean relative to us, this being determined by a rational principle, and by that principle by which the man of practical wisdom would determine it. Now it is a mean between two vices, that which depends on excess and that which depends on defect; and again it is a mean because the vices respectively fall short of or exceed what is right in both passions and actions, while virtue both finds and chooses that which is intermediate. Hence in respect of its substance and the definition which states its essence virtue is a mean, with regard to what is best and right an extreme" (Nicomachean Ethics, Book II, Part 6).

The main argumentative point made by that doctrine is that -even though it might be one's duty to pursue the mean (so as to both avoid the personal downside of "excess" or "defect" as well as to get along with others),- intellectualized knowledge of the ethical imperative and the actualization of ethical conduct are in no way synonymous. Each individual, that is, has to first intentionally practice the ethical path (by frequently repeating right actions) in order for ethical "conduct" and virtuous "judgment" to become second nature for them.

"Again, of all the things that come to us by nature we first acquire the potentiality and later exhibit the activity (this is plain in the case of the senses; for it was not by often seeing or often hearing that we got these senses, but on the contrary we had them before we used them, and did not come to have them by using them); but the virtues we get by first exercising them, as also happens in the case of the arts as well. For the things we have to learn before we can do them, we learn by doing them, e.g. men become builders by building and lyreplayers by playing the lyre; so too we become just by doing just acts, temperate by doing temperate acts, brave by doing brave acts" (Nicomachean Ethics, Book II, Part 1).

This "practical" notion of character formation through initial and ongoing goal-directed "activity" lends itself to better self-application as well as to more reasonable expectations of others than does the older Socratic view. It also raises a whole host of related empirical questions regarding: the typical pattern and culturally specific sources of character development; the rigidity of particular bents of character; and even the relative control or malleability of human learning under usual versus unusual or psychopathological conditions (e.g., as in the case of decline of higher deliberative functioning due to physical exhaustion, extreme age, or disease).

Concluding Remarks for Section 1:

We have started with the ancient Greek philosophers because in this period from Thales to Aristotle nearly all of the fundamental "metaphysical" positions which any kind of inquiry into the world can take are discovered, represented, or worked out in some form. If we grant that metaphysics (philosophical assumptions regarding ontology, epistemology, ethics, or logic) is important for establishing a sound "methodology" of science (how to proceed systematically in answering questions or investigating various aspects of worldly events), then we can better appreciate the value of obtaining a feel for the range of issues and types of solutions put forward during even this ancient period of Greek thought.

Presocratic philosophy begins with the ontological issues raised by Thales who believed the world was water. This initial departure from the traditional theistic or mythical way of thinking about the world toward a "naturalistic" one, constitutes a radical transformative shift in our collective intellectual life. The attempt by Thales to account for the cosmos in terms of water is a momentous departure because it seeks the explanation of worldly events in the world itself. His notable inclination toward naturalistic analysis remained a central feature of all subsequent technical or practical human activity, and it eventually provided a starting point for systematic scientific endeavor (Section 2).

Such intellectual advancements do not, however, take place steadily along unimpeded strait linear lines. They have a tendency to take the form of recurring -albeit upwardly mobile- cycles of speculative, technical, evidential, or argumentative progress and degeneration. The ancient Greek philosophical period is our first exemplar of this historiographic point but we will encounter many others.

From Thales to Democritus, we have an implied and then explicit "materialist metaphysic" being worked out. Democritus in particular, begins by criticizing Anaxagoras for introducing "nous" (a generalized amorphous mind) as an abstract principle that gave order to worldly events or motility to living organisms. Instead of seeking such external forces from outside the realm of material substance which impart motion to it, Democritus regarded the inherent movement of "atoms" as a fact of existence for which there was no further explanation required. In this, he can be said to have been drawing upon (and elaborating further) the distinctive feature of the Presocratic naturalists like Thales and Heraclitus who sought out explanatory principles in the objects or processes under study.

Of special interest to us, Democritus and his followers put forward what can be described as a substantive theory of individual mind (or thought) in which thinking was conceived of as a special kind of motion. The "substance" aspect of this crude anticipation of later psychological theory can be appreciated when we note that the "Atomists" talked of the body as composed of course atoms and the soul or mind as being composed of fine, smooth, round atoms. Despite the speculativeness and inconsistencies of the theory, the important point is that its very proposal bears witness to their determination to bring all phenomena (including that of individual thought) under the single all-embracing mode of a materialist explanation. These efforts were carried out, of course, on the basis of very inadequate understanding of material processes and of what would later be called biology or physiology.

The speculative strivings of these Presocratic materialists led subsequent Greek philosophical figures to become rather skeptical. The earlier debates over what constitutes the fundamental material element or constituent of the cosmos (water, fire, or atoms) struck them as providing equally plausible argumentative alternatives among which it was still impossible to decide. With the Sophists (e.g., Parmenides, Zeno), whose daily bread was contingent upon providing influential arguments to a paying clientele, the analytical efforts of Greek philosophy moved away from such ontological questions (regarding the nature of objects) toward epistemological and logical questions regarding the nature of arguments.

Although Parmenides still struggled to make a distinction between the "way of truth" and the "way of appearance" (Ring, 1987), subsequent Sophists -such as Protagoras, or Gorgias of Leontini in Sicily (483-375 BC)- are said to have wholeheartedly adopted a noncommittal "idealist metaphysic" of a peculiarly subjectivist stripe. This "subjective" position reflects a tactical equivocality regarding truth and a view that certainty of belief (if it exists at all) is purely personal. Under it, the individual man becomes the "measure of all things" and what is considered as true, right, or virtuous depends upon persuasion or power.

This Sophistic philosophy, however, was clearly problematic with respect to establishing any firm ethical standards and (as Russell indicates below) it was not typically intended for those purposes:

"What they had to teach was not, in their minds, connected with [truth,] religion or virtue. They taught the art of arguing, and as much knowledge as would help in this art. Broadly speaking, they were prepared, like modern lawyers, to show how to argue for or against any opinion, and were not concerned to advocate conclusions of their own. Those to whom philosophy was a way of life..., were naturally shocked; to them, the Sophists appeared frivolous and immoral.

.... The Sophists were prepared to follow an argument wherever it might lead them. Often it led them to scepticism [or even solipsism]. One of them, Gorgias, maintained that nothing exists; that if anything exists, it is unknowable; and granting it even to exist and to be knowable by any one man, he could never communicate it to others....

...[T]here were [occasional figures], in the Athens of the late fifth century, who taught [Sophistic] political doctrines which seemed immoral to their contemporaries, and seem so to the democratic nations of the present day [-i.e., the W.W.II era in which Russell is writing]. Thrasymachus, in the first book of the Republic, argues that there is no justice except the interest of the stronger; that laws are made by governments for their own advantage; and that there is no impersonal standard to which to appeal in contests for power. Callicles, according to Plato (in the Gorgias), maintained a similar doctrine. The law of nature, he said, is the law of the stronger; but for convenience men have established institutions and moral precepts to restrain the strong. [This latter doctrine has] won much wider assent in our day than ... in antiquity... [but was] not characteristic of [other or most] Sophists" (Russell, 1946, pp. 94-95).

In any case, Socrates eventually attempts to counteract the shortcomings of Sophistic philosophy. He proposes an "objective" idealist position in which "self-knowledge" (obtained by way of two-sided dialog) was advocated as: (1) a means of distinguishing "essence" from "appearance"; and (2) a path to discovering the "virtuous" life.

Under Plato and Aristotle we have a fuller elaboration of this new "objective idealist" position. Plato, however, rejected not only the Sophist's confusion of perception or persuasion with "knowledge," but also the Heraclitean "doctrine of flux." He didn't like Sophists, but he is said to have really despised Heraclitus. The truth he sought was an eternal "absolute ideal truth" abstracted from (rather than embedded within) the particulars of imperfect material existence or individual personal experience. Such absolute "Ideas" are revealed to the philosopher by way of "reason" which abstracts them out from the mere experience of particular "material" things as presented to the ordinary person by way of the "senses." This abstract version of objective idealism then guides Plato's theory of a utopian social structure, which (as we noted) was far from democratic.

In Aristotle's philosophy we see a peculiar tension arising between his own strivings toward a relational monism and the absolute (though objective) idealism handed down to him by Plato. Most notably, this is manifested in the tension between his naturalistic doctrine of the "four" causes on the one hand, and -on the other- the dual influence of: (1) his discursive doctrine of formal "logic"; and (2) his retained absolute idealist notion of "lawfulness" in nature as that which is "exceptionless" (see Section 2 for further elaboration on this latter point).

Our recognition of the inconsistencies residing in Aristotle's Idealist philosophy, however, should be tempered with an appreciation for the remarkable range of topics which he addressed. It is with his writings that we get the first indications of what we recognize today as scientific questions of the biological and psychological sort. In both, Aristotle is a source of later inspiration and error, but the fact that he addresses them at all illustrates that some kinds of objective idealism can (to a point) serve -just like a materialism- as a practical ontological basis for scientific investigation and thinking. The proviso to note in this regard, however, is that in Plato's hands, objective idealism of the "absolutist" otherworldly stripe was anti-naturalistic and by extension a nonscientific philosophy. Aristotle is interesting, therefore, because he attempts to restore various aspects of the former naturalistic approach (of Thales through Democritus) while introducing a new discursive logic and other useful methodological tools (especially his teleological notion of "Final" cause) along the way.

The "Methodological Cycle" and its relevance for Psychology

By way of closing down this initial Section and preparing you for what follows, three concluding comments are in order with regard to the roughly upwardly mobile methodological cycle of speculation, evidence and argumentative degeneration alluded to above.

Firstly, when we consider this whole era of Ancient Greek thought (Thales through to Aristotle) from our privileged vantage point of some two millennia on, an interesting pattern emerges which can be argued to take the form of an initial spin of a methodological cycle. What started as a very simple enterprise to discover what the world is like (ontological questions) begins to branch off into questions of epistemology, ethics, and logic.

The progressive intention of the Presocratic naturalists was to bring the cosmos under a materialist explanation, but due to the tentative and speculative flavor of their account, they didn't pull it off very well. This initial period of materialistic analysis didn't seem to resolve the theoretical questions it raised and was followed by the sceptical idealist position of the Sophists.

Socrates, who is considered as the dividing line between what went before and that which came afterward, recognized subjective idealism as a potentially disastrous position (where argumentative epistemology was valued above all else), and attempted to assert an admittedly flawed objective idealist position in its place. By doing so, he raised the further issue of ethics (a.k.a., values) to a prominent place in his metaphysics.

By the time we get to the "Classic period" of Plato and Aristotle we have the makings of a more complete philosophy that deals with questions of ontology, epistemology, logic, and ethics. What's more, if we give a charitable reading to the naturalistic aspects of Aristotle, it can be argued the cycle of argument, evidence, and further speculation seemed to be starting again. For the most part, Aristotle's account of psyche fits in quite well here because it moves well beyond the immediately prior rather speculative abstractions of Plato to become an argument

for the pursuance of a near-functional psychology concerned with investigating various forms of real life activities.

From our historical vantage point, we can recognize that such potential was not in fact realized (actualized in practice) but was rather interrupted by the so-called "Dark and Middle Ages" in which monastic forms of "Platonism" predominate amongst the small educated classes of Europe. But it should be at least conceivable that the makings for a new, more sophisticated spin of the philosophical and investigative cycle was there in Aristotle to some degree or other.

Secondly, this notably sequenced cyclical pattern will be seen to repeat itself in later sections of this work. We will note in Section 2 that during the 17th-18th century, the early thinkers (Bacon, Galileo, Newton) all put forward fairly simplistic materialists positions, but when subsequent figures (like Descartes, Locke) begin to philosophize, the issues begin to get rather complicated -just as they did with the Ancient Greeks- until we get to Hume (in the last part of the 18th century) who advocates a skeptical position because he views the prior era of argument as not making sufficient headway. Hume will play the unhappy role of our late 18th century Protagoras. He calls attention to the methodological gap existing between earlier ontological argument and its assumed epistemological and implied logical basis.

Still later in this work, we will note that during the founding years of psychology as a scientific discipline through to its elaboration into the somewhat standardized North Americanized discipline of "General Psychology" proper, the cycle of inquiry and discourse begins to accelerate, repeating twice in roughly 40-50 year intervals (between 1890 and 1929, and again from the mid-through-late 20th century). Following each cycle there was also a variable period of utter disciplinary confusion and rumination before the next discernible cycle started up again. For those of you paying careful attention to the above two lines, you will have reasoned that I am asserting that a new cycle has in fact recently begun and that my work is being presented to you as an upwardly mobile part of that current cycle.

Thirdly, even though I will eventually argue that the current cycle will likely reach an apex, take a downward turn for the worst, and have to to be repeated again in 21st century psychology, -for the simple fact that "Those who [don't bother to] remember the past are condemned to repeat it" (Santayana, The Life of Reason, Vol. 1, 1905)- I want to assert (here and now) that it needn't necessarily do so. This is because with each of the previous rotations of the cycle, valuable methodological "object lessons" have been deposited on the upper (progressive) and lower (problematic) peripheries which -if heeded- constitute a prescriptive plan for how to proceed from here on forward.

Recognition of the methodological cycle itself, then, constitutes our first valuable object lesson. Our knowledge of it will help us ascertain the difference between the truly progressive methodological departures or theoretical advances encountered throughout the remainder of this work versus the various rehashes of old impoverished approaches or theories which: either go nowhere; are counterproductive because better alternatives already exist; or are dangerous due to the discriminatory and inequitable policies which they promote.

Posted while in progress: May, 2003-April, 2006; Last update: April & August, 2008.

http://www.igs.net/~pballan/Toc4.htmDr. Constantine G. Niarchos

Nicolaus of Methone's Criticism on Proclus' "Theory of «Participated» or «Unparticipated» Intelligence" (NOUS)

From Yearbook of the Research Center for Greek Philosophy, at the Academy of Athens, 13-14 Athens 1983-1984.

A. The concept of Participation

The question about the «unparticipated» and the «participated» being which appears very often in ancient philosophy can be considered as parallel to the problems of the One and the problems of the Many. In this paper Ι intend to explore some of the ways by which Greek philosophers, and especially Proclus, the neoplatonist, approached such problems and in particular the «unparticipated» and «participated Nous».

The theories of Proclus were widely commented on by Nicolaus, Bishop of Methone, a scholar of the twelfth century Byzantium, who attempted to resist against the penetration of doctrines, such as nominalism etc., into Christian dogmas(1). His criticism is based on the comparison of Proclus' theories with logic and conceptual consistency, and their relation to traditional Christian beliefs (2).

Proclus examines the nature of the relationship that enables something to possess its individual characteristics; this is for him a central problem of ontology, which is mainly focused on this relationship, existing only in actuality. The concept of «participation» had been elaborated in Plato's 'Parmenides' (130a-132d) and in Plotinus' 'Enneads' (VI, 9, 2) (3). In Plato, participation explains the relationship between the Forms (Είδη) and the sensible particulars (αισθητά) as it is illustrated in the 'Phaedo' (100d) and the 'Parmenides' (130c131a). Some element of the form in its complete purity is really contained in the entity. Such a concept is clearly much closer to Plato than to the «imitation» (μίμησις) of the Pythagoreans (4). This exclusive relation between forms and sensibles includes causality; Plato states that it is more than a declaration that all predication about particulars includes the rational relation of particular to universal. The forms are not mere logical entities; they are real existents in such a sense that their presence in sensibles and the communication in them by sensibles, are at least conceivable terms to express the relation in question (5). There is no doubt that the communication of forms is achieved through participation only and Aristotle himself confirms that most of the things, which are ομώνυμα exist through the fact of participation in them (6). Plato, on the other hand, extended the range to include all things συνώνυμα with the forms, but Aristotle cannot accept this as it would illogically apply to things which had no forms. In the 'Parmenides' (133d) Plato applies the ομώνυμον without distinguishing it from συνώνυμον, whereas by contrast Aristotle in

his criticism of the Theory of Ideas describes the ομώνυμον, as denoting no real common nature with the particulars(7). The main problem still remains, whether the forms are merely ideas or concepts; this question is actually raised in the Platonic dialogues, only to be denied (8). Proclus appears to be a consistent student of Plato's doctrine of communication of forms and echoes his master's voice that: «all things are in all things, but in each after its own fashion» (9). Yet, Plotinus had adopted it in dealing with the general relationships of Intelligibles, while Porphyr and Iamblichus employed the theory as a suitable way of filling the unexplained gaps remaining from Plotinus' explanation of the world of experience, in order to maintain the unity of the system and reconcile opposing concepts(10).

Proclus, by adopting the Aristotelian doctrine of matter and form, widens the definition of «participation» into a formula for the relation between higher universal (as hypostasis or Platonic form), and the lower «particular» as spiritual or material individual; it is an immanent universal which is directly participated(11). The transcendent universal influences the particulars ως εφετόν, like the Aristotelian god, or possibly as ελλάμπον, since it is strictly unparticipated(12).

Concerning the relationship between forms and particulars Proclus states that, if the forms are linked with particulars by similarity (omoiotis), then, there would be infinity of related causes. Instead of rejecting substantive forms completely in the manner of Aristotle, he saw the relationship as representing ομoίωσις than ομoιότης as qualifying only one of the related terms. Thus the form exists in an entirely separate realm; nevertheless to secure the operational function of the form, the particulars must be in some way similar to the form in that they are caused by it(13). It is therefore clear that through this participation in the one, no element of plurality is allowed to affect the status of the one. This excludes the concept of some neoplatonists, who considered the one as including the many in a seminal manner, as well as with the Stoic immanetistic approach. This doctrine was further elaborated by Dionysius the Areopagite(14).

The entire meaning of the concept of «participation» is focused on the inter-relationship between the participated and the participant and it is explained by six general terms: the cause, its power, its activities, the power of its activities, their potential power, and finally the participant itself with its potential power to receive the participated. The participated; being of a certain kind by its very nature is notable for its own existence (καθ' ύπαρξιν), while its participant exists only by participation (κατά μέθεξιν). Thus, whatever exists is what is either as a cause by its existence (καθ' ύπαρξιν) or by participation (μέθεξιν)(15). The καθ' ύπαρξιν often happens according to essence (κατ' oυσίαν) or εssentially

(oυσιωδώς) and by participation (κατά μέθεξιν) is often represented by irradiation (κατ' έλλαμψιν) or εικoνικώς(16).

Β. The Henads

Proclus, being under influence of earlier Neoplatonists adopts a class of participated forms of the one; these forms, proceeding from the one, are termed by him as henads. The doctrine of the divine henads is a special modification of the Plotinian world-scheme by later Neoplatonists. In Plato they denote merely units or examples of ones, but Proclus interprets them as: (a) forms or monads in the world of being, and (b) beings in their transcendental unity (Pythagorean influence is evident here)(17). But how can a henad, being itself unique and participated, be at the same time self subsistent and also of necessity in subjects? The theory of separable participation on the lines of Porphyr's doctrine of deity, suggested by Proclus, could be the answer: through this solution the henad is everywhere and nowhere. Spatial intervals are not demanded for the henads, because, transcending everything without relation, they are present everywhere without admixture (l8). This follows the answer by Socrates to the question raised by Parmenides, of how a form can be present entirely in each participant: that it could be compared to the daylight, which, though one and the same light in many places simultaneously, still preserves its individual unity. Proclus insists that the unparticipated term, as transcendent form, is entirely present in the participated form. He establishes his theory of unparticipated principles by demonstrating that they are self-subsistent, in the sense that their appearance denotes a new face in the procession of individuality of the one, which serves as their archetypon of all unity (19). This unity is the henad of the soul which ascends to it through a strict process of dialectical discipline. Thus, the henad of the soul is regarded not as an intellect but as a participated one and its unification with the unparticipated Being takes place beyond the realms of intellectual virtue (20).

There are, in the system of Proclus, different types of henads: the intelligible henad (=unparticipated being), intelligible and intellectual (=unparticipated life), intellectual (=unparticipated intelligence), supercosmic henad (=unparticipated soul), intercosmic henads (=representing the divine participated souls and the bodies they animate). The henads so listed do not in fact belong to the particular order of the name indicated; rather they are regarded as the transcendent source of all things. There appears a contradiction between the participation and the imparticibility of the first member of the transverse henads; in the simple explanation the one stands as the first member of the first transverse henads with no attention given to distinction of the second hypostasis (21). For Proclus the basic issue was that the same attribute, or even the same god, can exist on successive levels in an appropriate mode.Such attributes are

present perfectly and unequivocally only in the realm of the henads. Thus, intelligence has self-sufficiency by participation, the soul by illumination and the sensible world by its resemblance to the divine, while the gods are self-sufficient by their very nature (22).

Theologically, as Zeller states, the gods represent the traditional deities of Greek mythology and, according to Proclus, the highest task of Platonic philosophy was the exact classification of all these deities, with the defect, however, of robbing them of individual personality, through the principle of vertical procession, each deity being split into a series of diminishing forces(23). In addition, these gods are bound together by a closer collective unity than any subsequent order of existence. Plotinus put all gods within Nous, whereas Proclus places them mostly in the first hypostasis; confusedly, however, he applies the term gods to numerous entities such as eternity, time, and even the sensible world -which was described as «intelligible», intellectual» or «intra-mundane». The traditional ancient gods had somewhere to be included on a lower level, being participable and not belonging to the abstract unity of the First Hygostasis.

The henads are participable according to the general rule (24): in each order there is an intermediate class of predicable terms linking the non-predicable substantive principle with concrete subjects and the «unities» link the non-predicable substantive unity with the concrete united. Proclus does not make clear how to reconcile this particibility with the υπερουσιότης of the henads, but there is no immanence in the ordinary sense. They are: (a) separately participated (χωριστώς μετεχόμενα) -like all αυθυπόστατα, and (b) they are transcendent in a special degree or manner (25). The main problem is to demonstrate that an imparticible henad could only be distinguished from the one by imputing to it falsely and to a lower degree of unity, which can always be analysed into a participable henad and the participant. Like the One, henads are without any internal differentiation; their essential predicate is their unity or goodness, other attributes being only κατ' αιτίαν implicitly. Henads are also measures of ousia, principles of its articulated structure, as time and eternity are the measures of actuality (26).

C. Nous (Intelligence)

In the entire system of Proclus the concept of Nous lies as the basis of his own philosophical. speculation. Every divine intelligence is perfect and possesses the characteristic of unity; it is the primal intelligence from which all others derive their own existence (27). This statement is criticised by Nicolaus who reminds us that the only source and cause of the existence of every being is God, whom he calls «supra-Intelligence» (υπέρνοον). He bestows by his own act substantiality upon all other intelligences. In no case the perfection

of God depends on the participation of others in him, for he is the expression of full divinity (28). All other intelligences are close to One, divine and perfect, due to the participation in the Primal Intelligence (29).

Proclus' approach to the divine Intelligences and their relationship to other objects is more complex than Plotinus'(30). We discern three levels: (a) The πρώτως νoητόν, comprising the true being (οντως ον) and life (ζωή) does not coordinate with Intelligence but perfects it, without loosing its transcendence, but represents the divine νοητόν(3l). Its cognitive element is only κατ' αιτίαν, as the source of the content for the highest Intelligence, which, as it is stated in Plato's 'Parmenides', has no prior intelligible Object(32).(b) Nous νοητός is similar to the Plotinian nous with subject and object only logically distinguishable (εν κατ' αριθμόν); the lowest member of the intelligible triad is apparently identifiable with the πρώτος νους(33), and with the unparticipated intelligence(34). Here one traces similarity to the παντελές ζώον of the 'Timaeus'(35).

(c) Α series of inferior intelligences know their objects by participation and by reflection. The highest of these is the demiurge of 'Τimaeus'(36).

Plato sometimes regards the demiurge as the model for the sensible world, but sometimes as something extraneous (37). Numenius and Amelius supported the latter view as stated in 'Timaeus' (39c-e), where nous is separated from its objects (38). Proclus rejected the proposed triad of divine principles. On the other hand, Plotinus opposes Numenius' interpretation as being gnostic, by reaffirming his known maxim: «ουκ έξω του νου τα νοητά» (39).

Το Porphyr the demiurge was a soul, possessing nous as his model; so he achieved a natural interpretation, keeping also the Plotinian equation between νους and νοητόν(40). Theodore of Asine revived Amelius' concept and Proclus influenced by Syrianus, attempts to harmonize this with Plotinus, while also clarifying Platonic contradictions; thus, the παράδειγμα is partly superior to the demiurge and partly immanent in him(41).

There would be found three elements in each intelligence: its existence, in its intelligible content (νοητόν); its potency, which is its power of intellection (νους);its activity, the act of intellection (νόησις). Their combined function represents the mark of eternity. Aristotle links it to the divine nous(42).Nicolaus observes that the «activity» differs from the potency, both of which exert no influence upon the immaterial intelligences. The potency exists only in «imperfection», thus in no case it would apply to the primal Intelligence, and the activity is therefore of no substantial use (43).

Proclus defines six grades between the pure unity of the One and the minimum unity of matter: (a) The henads, as transcendent sources of plurality; (b) the intelligences, each one being an actual plurality (πλήρωμα ειδών), but indivisible in time or space(44); (c) souls, spatially indivisible, but their activity temporarily divisible(45); (d) inseparable potencies and immanent forms, subject to the bodies spatial divisibility(46); (e) corporeal magnitudes divisible at any point(47); (f) dispersed corporeal manifolds actually divided in space.

Plotinus and Porphyr adhered to approximately similar distinctions, but without the henads. Proclus insists that every intelligence is an indivisible existence. Its indivisibility is due to the lack of magnitude, body or movement. This statement was refuted by Nicolaus who considers the intelligence to be movable; the henads cannot comprise the first manifold upon which the intelligences are consequent (48). That every intelligence, though a manifold, according to Proclus, in fact is a unified manifold, seems to Nicolaus to be absurd. If every manifold participates in some way the one and remains united, then what is divisible? That, though a manifold, does not participate the one? And if participates the one, how can the one intelligence be manifold? Again, if it is manifold how can be indivisible and manifold at the same time? So, the intelligence as manifold is placed second, after the first, the group of henads. For Nicolaus it is only the nous that remains indivisible, being itself incorporeal, without magnitude, or possessing all kinds of plurality. Even its activity is single in itself but being dispersed to many things (49).

Every intelligence is intellectually identical both with its priors and with its consequents, especially the latter as their cause with the former by participation.The Neoplatonists sought a middle path between: (a) Aristotle's view of the intelligence being of its own object, and (b) the intelligence's awareness of the corporeal world. Plotinus says that intelligences can contemplate in the lower realms. To Proclus the answer is found in the expression: all things are in all things, but in each according to its proper nature («πάντα εν πάσιν, οικείως δε εν εκάστω»)(50), which is rejected by Nicolaus, i.e. how can the prior and the great be in the posterior and the small(51)

Notes

1. Cf. Proclus, 'The Elements οf Theology'.Α revised text with translation, introduction and commentary, by Ε.R. Dodds, Oxford U.P. 1963. Nicholaus of Methone, 'Refutation of Proclus' Elements of Theology (Νικολάου Μεθώνης, 'Aνάπτυξις της Θεολογικής

Στοιχειώσεως Πρόκλου Πλατωνικού Φιλοσόφου'). Α critical edition with an introduction on Nicholaus' life and works, by Athanasios D. Angelou, Athens -The Academy of Athens Ε. J. Brill, Leiden 1984. Also see: Nicolaus Methonensis, 'Ανάπτυξις της Θεολογικής Στοιχειώσεως Πρόκλου Πλaτωνικού Φιλοσόφου', by pages and lines of Voemel's Text, in Greuser's 'Initia Philosophiae', pars IV, Frankfurt 1825. From now on references will be made on Angelous' critical edition, as: Nicolaus of Methone.

2. Cf. Α. Demetracopoulos, Bibliotheque ecclesiastique Ι, 232, in Byzantinische Zeitschrift, 8 (1889), pp. 263-301. Also see: Β. Τατάκη, 'Η Βυζαντινή Φιλοσοφία', Athens 1977, pp. 209-211.

3. Proclus, 'Ε.Τ'., props. 1-6, pp. 1-6; Idem, 'Ιn Parm'., p. 1220.3. Also see Idem 'E.Τ.' props. 31-34, pp. 34-36. Plato, 'Republic' VII, 519b.

4. Cf. Aristotle, 'Metaphysics' Α 6, 987b. Aristotle states that the explanation of imitation derives from the Pythagoreans, who held that things «imitate» numbers. Although imitation, as applied to sensible particulars, falls into disuse, the concept that the «intelligible world» is the example for the sensible world, remains current in later Platonism and especially in Neoplatonism, cf. Plotinus, 'Enneads' V, 8.12. Just as the sensibles are contained in some sort of organic unity that is the world, so the forms exist in some «intelligible place». See also, Plato 'Republic' VI, 508c.

5. The expression «κόσμος νοητός» is located «beyond the Heavens» as it is stated in 'Phaedrus' 247c. The image becomes sharper in 'Timaeus' 30c-d. For Plato, the Forms do exist separately ('Timaeus' 52a-e), and the reasons may be sought in epistemological considerations as well as in the ethical ones that troubled Socrates and that were almost certainly operative upon Plato. See also, 'Philebus' 33d-34a; 'Timaeus' 64a-d.

6. Cf. Aristotle, 'Metaphysics' Α 9, 990b 28-31; Ζ 12, 1037b 19.

7. Idem op. cit., 991a 5. Aristotle uses the term «ομώνυμον» rather than «συνώνυμον», partly perhaps to suggest that there is nο common nature shared by the Idea and the particular, and therefore the one can do nothing to explain the other. Cf. W.D. Dodds, 'Aristotle's Metaphysics', vol. 1. Oxford U.P. 1970, pp. 190-191.

8. Cf. Plato, 'Parmenides' 132b-c; 134b.

9. Cf. Porphyr, 'De Abstinentia Χ' (Nauck); Syrianus Ιn 'Metaph.', p. 82.l.

10. Cf. Plotinus, 'Enneads' Ι, 1, 7.12-13, III, 2, 14.9; in relation to Plato, 'Enneads' V, 1, 9.9-11, in relation to Aristotle, 'Enneads' V, 1, 9.15-Ι6; Proclus, 'Ιn Remp.' ΙI, 77 (Kroll).

11. Cf. Proclus 'Ιn Parm.' 1069.23. An «ένυλoν είδoς», a «ψυχή εν σώματι».

12. The fact that everything turns towards God in prayer, except the First, as a natural process reflected everywhere in creation, is an indication of the dependence of the many on the Suprem One. Cf. J.M. Rist, 'Plotinus, The Road to Reality' Cambridge 1977(2), pp. 199-212. Also see Ε. Peterson, «Herkunft und Bedeutung der ΜΟΝΟΣ ΠΡΟΣ ΜΟΝΟΝ Formel bei Plotin», 'Philologus' 88 (1933), pp. 30-41, and Ε.R.Dodds, «Numenius and Ammonius», 'Entretiens Hardt' 5, Geneva 1960, pp. 16-17. In Plato's 'Symposium' 217b the union with the Supreme Good could have had a special meaning to the Platonists. For the problems concerning the tendency of the soul to return back to its source see J.M. Rist, 'Eros and Psyche', Toronto 1964, pρ. 86.

13. Proclus, 'In Parm.', 906 sq. Idem, 'E.Τ'. 29: 34, 3, where the «ομοιότης» is defined as a cosmogonic principle and it is probably inspired by the Platonic texts «νoμίσας μυρίω, κάλλιoν όμoιoν ανoμoίoυ» ('Timaeus' 33b; Proclus, In 'Tim.' ΙI. 78. 12 ff.). Similarly Porphyr says that real Being «την πάσαν ετερότητα διά της ταυτότητος υπέστησεν» (αφ. XXXVI).

14. Cf. Dionysius the Areopagite, 'De Divinis Nominibus', 13, 2 (PG. 980a): «και oυδέν έστι των όντων, ο μή μετέχει πη τoυ ενός τoυ εν τω κατά πάντα ενικώ ... και άνευ μεν τoυ ενός oυκ έσται πλήθoς, άνευ δε τoυ πλήθoυς έσται το εν».

15. Cf. Proclus, 'Ε.Τ.', props. 65 and 67, pp. 62-66. Idem, Ιn 'Tim.' Ι, 8.17 sq.

16. Idem, 'Ε.Τ.', props. 64-67, pp. 60-61. Idem, 'Ιn Crat.', 28.23 (Pasquali). Cf. E.R. Dodds, op. cit., pp. 234-235.

17. Cf. Plato, 'Philebus' 15a.

18. Proclus, 'Ε.Τ.', prop. 98, pp. 86-88. In Plato's dialogues it is clear when Parmenides asks Socrates how a form can be present in its entirety in each of the participants, Socrates suggests that it might be like the daylight, «which is one and the same daylight in many places at once, and yet keeps its undivided unity»; but his questioner ignores the suggestion of 'Parmenides' 13lb. See E.R. Dodds, op. cit. pp. 251-252.

19. Proclus, 'Ε.Τ.', prop. 40, p.42; props. 113-127, pp. 100-112. Cf. R.T. Wallis, 'Neoplatonism', London 1972, pp. 146-159.C.G. Niarchos, 'Language and the Transcendent Reality in Ancient Greek Philosophy', Athens 1984, 63-67 (in Greek).

20. Proclus, 'Ε.Τ.', prop. 140, pp. 124-Ι25. Idem, 'Ιn Remp.' ΙI. 232; Iamblichus, 'Myst.' 115.

21. Cf. R.T. Wallis, 'op. cit.' pp. 151-153, Maximus the Confessor, Ambiguorum liber, PG 91, 1088c. For Maximus «deification» is the participation of the «whole man» into the «Whole God». Also see J. Meyendorf, 'Byzantine Theology', Oxford 1975, pp. 163-164.

22. Proclus, 'Ιn Plat. Theolog.' Ι, 19.16-17 (Portus). New edition by Saffrey-Westerink.

23. Proclus, 'Ιn Tim.' ΙlΙ, 10.7.

24. Idem, 'Ε.Τ.', prop. 23, p. 26. The transcendent universal must exist, in order to give unity to the many immanent universals and must be distinct from any of them.

25. Idem, 'E.Τ.', prop. 130, p. 116. Proclus is inconsistent here. Sometimes he refers to all henads, other than the one, but sometimes he excludes the super-cosmic gods. Cf. Idem 'In Tim.' Ι, 226; III, 204. 16. R.T. Wallis, op. cit. pp. 151-153.

26. Proclus, 'E.Τ.', prop. 54, p. 32. The traditional Academic definition of time was «the measure of movement» (Aristotle, 'Physics' Δ 220b 25; 'Definitions' 41lb). Plotinus' objection refers to the absence of a certain definition, for the above mentioned theory tells us what time is used for (Enneads ΙII, 6, 9.12-13). Proclus' theory on time is based on the Plotinian concept in order to stress its reality as something independent of and higher than its content, against the Aristotelian doctrine which made it a «πάθος κινήσεως» ('Physics' Ζ, 251 b 28) and a «αριθμητόν», something itself counted or measured ('op. cit.' Δ, 220b 8), cf. Proclus, 'Ιn Tim.' ΙII, 4.23 ff. Nicolaus asks Proclus: why «every eternity», when there is only one? It is known that each of the immanent eternities is the measure of its participant eternal and in turn it is measured by the transcendent Eternity. Cf. also E.R. Dodds, 'op. cit.', pp. 228-229. Nicolaus of Methone, 'op. cit.', pp. 56-57.

27. Proclus, 'Ε.Τ.', prop. 160, p. 140. For Plotinus Being and Intelligence had been coordinate and only logically distinguishable; for Proclus all Intelligence is Being, but not all Being is Intelligence (props. 101-102). The Being which itself is not Intelligence is distinguished as «το όντως ον», and it is called «intelligible» not in the Plotinian sense as the content of the Intelligence, but as the transcendent source of that content. Cf. R.T. Wallis, 'op. cit.', pp. 152-153. Cf. Nicolaus of Methone, 'op.cit.', pp. 143-144.

28. Cf. St. Ρaul, 'Colassaeis', 1.19-20.

29. Cf. Nicolaus of Methone, 'op. cit.', pp. 143-144.

30. Proclus, 'Ιn Plat. Theolog.', 105; 'In Tim.' 1, 321; ΙII, 101.1 ff.

31: Idem, 'Ε. Τ.', prop. 181, pp. 158-160. Nicolaus of Methone, 'op.cit.', pp. 157-158. 32. Proclus, 'Ιn Parm.', 900.26.

33. Idem, 'Ε.Τ.', prop. 160, p. 140. Nicolaus of Methone, 'op.cit.', pp. 143-144. Cf. H.J. Blumenthal, 'Plotinus Psychology', The Hague 1971, p. 4. E.R. Dodds, 'Pagan and Christian in an Age of Anxiety', Cambridge 1965, pp. 24-26.Dodds argues that after Plotinus discussed the Gnostic view that the soul created the world out of 'tolma' ('Enneads' ΙI, 9, 11.21 f.) he dropped this way of looking at the soul's descent. J.Rist argues against Dodds in a review in 'Phoenix' 20 (1966) pp. 360 f.: his objections, however, are partly based on the contention that Plotinus never «held the Gnostic view that 'tolma' was the 'motive' for creation», a suggestion difficult to reconcile with passages like V.l, unless the stress be put on «Gnostic» rather than «motive». Cf. Plotinus, 'The Road to Reality', 'op. cit.' p. 257.

34. Proclus, 'Ε.Τ'., props. 101, p. 90; 166, p. 144; 170, p. 148. Idem, 'In Tim.' ΙI, 202.7.

35. Idem, 'Ιn Tim.' ΙIΙ, 101.3 ff.

36. Cf. Plato, 'Tim.' 30a-b. The demiurge is probably to be identified with the intelligent, efficient cause posited by Plato in 'Philebus' 27b (cf.'Sophist' 265c): But he is not omnipotent: he makes the 'kosmos' «as good as possible» ('Timaeus' 30b) and must cope with the counter effects of necessity (idem 47e-48a). In later Platonism the demiurgic function is performed by a secondary emanation, by the 'Logos' in Philo ('De cher.' 35, 136-137; Idem, 'De spec. leg.' Ι, 81) and 'Nous' in Numenius (cf. Eusebius, 'Praep. Evang.' ΧI, 17-18) and Plotinus ('Enneads' ΙI, 3, 18).

37. Proclus, 'Ιn Tim.' Ι, 323.32. Plato's description of the maker of the lower gods, the soul of the universe and the important part of the human soul is in 'Timaeus' 29d-30c; he uses the pre-existent 'eide' as his model (ibid). 30c-3la).

38. Proclus, 'In Tim.' III, 103.Ι8. Plotinus in an early essay (IIΙ, 9, 1) toys with the opinion held by Numenius that there is a higher Nous which is unmoved and separated from other objects, as well as a lower Nous which moves (cf. Eusebius, op. cit. ΧΙ, 18.20).

39. Cf. Plotinus, 'Enneads' V, 4, 2; VI, 6, 18.

40. Proclus, 'In Tim.' Ι, 306, 31; cf. E.R. Dodds, 'Proclus, The Elements of Theology, op. cit.', p. 286.

41. Cf. Plato, 'Rep.' VII, 514a-517e.

42. Plato connects «αιών» with «νοητόν» ('Tim.' 38a). Cf.Aristotle 'Metaph.' Λ 7, 1072b 26; Plotinus 'Enneads' V, 1,4.

43. Cf. Nicolaus of Methone, 'op. sit.', p. 149-151.

44. Proclus, 'E.Τ.', prop. 177, p. 156. Nicolaus of Methone, 'op. cit.', pp. 155-156.

45. Idem, 'E.Τ.', props. 191-192, pp. 166-168. Here emphasis is laid, upon the principle which participates both time and eternity, and is therefore at once a being and a coming- to be, i.e. the «μεθεκτή ψυχή», which is thus again found to be intermediate between the two words. Plotinus in 'Enneads' IV, 4, 15 states that only the passions of the soul exist in time and often reckons the soul among the rurely indivisible principles.

46. Proclus, 'E.Τ.', prop. 190, p. 166. See also Nicolaus of Methone, pp. 168-169. In Ρlato's 'Timaeus' 35a the soul is considered as the frontier between the two worlds and this conception dominates the Neoplatonic psychology.

47. Proclus, 'E.Τ.', prop. 80, p.74. Proclus held that magnitudes are potentially though not actually divisible to infinity, i.e. they can be divided at any point, but not at every point simultaneously. Cf. Aristotle, 'Physics' Γ 6, 206a 11 sq. Proclus In 'Tim.' Ι, 453.19.

48. Proclus, 'Ε.Τ.', prop. 113, pp. 100-102. Nicolaus of Methone, pp. 109-110. Cf. R.T. Wallis, 'Neoplatonism, op. cit.', pp. 148-149.

49. Cf. Nicolaus of Methone, 'op.cit.', p.110.

50. Proclus, 'Ε.Τ.', p: 92. E.R. Dodds (op. cit., p. 254) observes that the statement «all things are in all things, but in each after its own fashion» is ascribed by Syrianus (in 'Metaph.' 82.1ff.) to the Pythagoreans and by Iamblichus (ap. Stob. 'Ecl'. Ι. xlix. 31, 866 Η) to Νumenius. Yet, this sentence covers all gaps left by Plotinus in his derivation of the world of experience and bridged oppositions without destroying them. Proclus makes use of it not only to interprete the Platonic «κοινωνία ειδών» (cf. 'Ιn Parm.' 751 sq) and to give some solutions of the difficulties concerning the theory of Parmenides about transcendent Forms, but also to link together the four material elements (cf. 'Ιn Tim.' ΙΙ, 26.23 sq). This statement was taken over by Dionysius the Areopagite (e.g. 'Div. Nom.' 4, 7, PG 3, 704 c: αι πάντων «εν πάσιν οικείως εκάστω κoινωνίαι»).

51. Cf. Nicolaus of Methone, 'op. cit.', pp. 99-101.http://www.myriobiblos.gr/texts/english/niarchos_proclos1.html

550 BC - Pythagoras - the mathematical mind.

Pythagoras (582-500 BC) suggested that matter and mind are mystically connected. Logic, numbers, spirit, and soul were expressions of the same reality. He thought the soul to be immortal and wandering on a path of transmigration from one body to another. The Pythagoreans had a geometrical conception of the world. They believed that mind is attuned to the processes of nature, in particular to the laws of mathematics. Mathematics is seen as the true essence of mind.

450 BC - Anaxagoras - the universal intelligence.

Anaxagoras (500-428 BC) introduced the concept of "Nous" (mind, reason) into Greek philosophy. Nous, the eternal mind, transforms chaos into order and through it the material world comes into being. The primordial One produces forms of multiplicity through dichotomisation. This process is originated and controlled by the power of mind, or Nous. According to Anaxagoras, mind is infinite and self-organizing. It is not intermixed with anything, but pure in its being.

450 BC - Alcmaeon - the dissected brain.

The Greek physician Alcmaeon (around 450 BC) concluded from his studies of dissection that the brain is the centre of intelligence. In doing so, he contradicted the mainstream theory of his time, which held that the heart is the centre of intelligence and seat of the soul. Alcmaeon also surmised that optic nerves conduct light from the eye to the brain and that the eye itself contains light.

400 BC - Hippocrates - the four humours.

Hippocrates (460-377 BC), the founder of Western medicine, is famous for the Hippocratic oath. He invented the notion of the four humours, black bile, yellow bile, phlegm, and sanguine, which he equated with the four elements. Hippocrates thought that disease arises from an imbalance of these four humours and that people can be healed by restoring their proper proportions. The dominating humour was also thought to be responsible for the temperament (black bile = melancholy, yellow bile =

bitterness and irascibility, phlegm = equanimity, and sluggishness, sanguine = passionate and cheerful).

Hippocrates correctly identified epilepsy as a brain disorder. He held that not only thought and reason, but also feelings and moods originate in the brain: "Men ought to know that from the brain, and from the brain only, arise our pleasures, joys, laughter and jests, as well as our sorrows, pains, grievances, and tears. Through it...we...think, see, hear, and distinguish the ugly from the beautiful, the bad from the good, the pleasant from the unpleasant."

400 BC - Plato - ideal forms and reason.

Plato (428-347 BC) plays an important role in the history of epistemology. His theory of ideas, which he presented in the famous cave allegory, can be seen as a precursor of both medieval realism and later idealism. Plato held that all forms of the physical world are merely instances of perfect forms in an ideal world. The idea of a table is the supreme form of table of which there is only one. It contains in itself all actual tables of the physical world. The knowledge of ideas, or supreme forms, provides intellectual and ethical guidance for humans. Plato thought that perfect forms have an actual metaphysical existence.

Plato divided the human mind into three parts: the rational part, the will, and the appetites. Ideally the will supports the rational element, which in turn controls the appetites. If the rational element is not developed, the individual behaves immorally, hence immorality is a consequence of ignorance. Furthermore, Plato distinguished between two kinds of conscious thought: opinion and knowledge. He said that all assertions about the outside world are necessarily based on sense experience, and are therefore only opinions. In contrast, he described knowledge as a higher form of awareness, because it is gained from reason rather than from sense experience.

350 BC - Aristotle - the three souls.

Aristotle (384-322 BC) equated mind with reason and thought it to be a property of the living soul. In contrast to Plato, who believed that body and soul are two different entities, he held that mind and body are intertwined in all living beings and are thus inseparable. Growth, purpose and direction are therefore built into nature. Aristotle proposed three forms of soul: 1. the vegetative soul possessed by plants in that they grow and decay and enjoy nutriment, but they do not have motion and sensation, 2. the animal soul which bestows animals with motion and sensation, and 3. the rational soul which is the conscious and intellectual soul peculiar to man. Each higher form possesses in full the attributes of the lower souls, which makes human beings the only possessor of all three types. Aristotle also proposed a theory of memory surmising that the

processes involved in short term memory (immediate recall) differ from those involved in long-term memory.

300 BC - Herophilus - the beginning of neuroscience.

The Greek anatomist Herophilus (335-280 BC) studied the human brain and recognised it as the centre of the nervous system. He distinguished the cerebrum and cerebellum and named the brain as the source of thought. Herophilus also made the first contribution to the field of neuroscience by distinguishing between sensory and motor nerves and by performing the most thorough study of brain anatomy attempted until the Renaissance.

300 BC - Pyrrho - scepticism as a state of mind.

The founder of the Greek school of scepticism, Pyrrho (360-272), stated that human mind is incapable of attaining true knowledge of anything, because ultimate reality is incomprehensible. Therefore, there is no objective knowledge, but only opinion. The best attitude one can develop in view of this fact, is to suspend any judgment completely, to free oneself from passions, and to calm one's mind. The idea that no person's judgment is more correct than that of another goes back to the first Sophist, Protagoras, who lived around 450 BC. Pyrrho developed scepticism into a more elaborate and consistent system of thought.

250 BC - Erasistratus - the brain and the vital spirit.

Erasistratus (300-260 BC) was an anatomist who worked one century after Aristotle. He found three tubular structures going to every organ of the body: an artery, a vein, and a nerve. He expanded Herophilus's theory of motor and sensory nerves by adding the thesis that all nerves are connected to and controlled by the brain. Erasistratus saw the brain as a mechanism for distilling the pneuma (the vital spirit), which he thought was flowing from the heart up to the brain and then down to the organs.

150 AD - Galen - the great Greek doctor.

Galen (129-199 AD) was the most influential physician of antiquity, after Hippocrates. He influenced medicine profoundly until about the 17th century. Galen synthesised the thought of Pythagoras, Plato and Aristotle and built upon the discoveries of Hippocrates and Erasistratus. He proved that the arteries carry blood instead of air (as the Greeks formerly presumed); and he demonstrated that the brain controls motion and voice. Galen further assigned the three largest organs of the body to be the seat of the three Aristotelian souls; the liver as the seat of the vegetative soul, the heart as the seat of the animal soul, and the brain as the seat of the rational soul.

For Galen, the rational soul was divided into the faculties of imagination, reason, and memory. He located these three faculties in the ventricles of the brain. Because the function of the brain was to distribute animal spirit throughout the body, to Galen it

seemed that the fluid filled ventricles perform this function and thus disregarded the white and grey matter surrounding the ventricles. According to Galen, the brain receives vital spirit (pneuma) from the heart, which is mixed into the sanguine humour (blood). The brain then separates the animal spirit out and stores it in the ventricles, from where it is distributed throughout the body via the nerves. This mechanism of circulating pneuma controls muscles, organs, and all of the body's activities.

250 AD - Plotinus - the emanation of mind from the Absolute.

Plotinus (204-270 AD) rejected Aristotle's notion of the soul not being able to exist without the body. Building mainly on Plato, he said that mind is a prisoner of the body. Plotinus held that soul is the immortal part of mind. It survives the death of the body and enters a series of transmigration from one body to another. Consequently, the soul is the only abiding reality of the human condition. Plotinus formulated a theory of emanation according to which mind emanates originally from the Absolute Being, or the One, and then forms Nous, the universal intelligence, from which the world spirit is formed in turn. Human mind, animal mind, vegetative mind, and finally matter all emanate from the world spirit. They are different manifestations of one universal intelligence.

400 AD - St. Augustine - the illuminated mind.

The church father St. Augustine (354-? AD) had an interesting idea about mind. He said that the human mind couldn't gain knowledge from sense perception alone. He also rejected Plato's theory of ideas. Instead, according to Augustine, knowledge is acquired on account of divine illumination. He argued as follows: The shape of an object such as a tree can only be seen by the eye, because the object is bathed in light. Similarly the mind can only recognise truths, such as the mathematical truth 1+1=2, because it is illuminated by the light of eternal reason. This light is not so much the source of ideas and knowledge, but the condition under which mind is able to recognise the quality of truth. In spite of the simplicity of this idea, or perhaps due to it, Augustine had a tremendous influence on the philosophers and theologians of the Middle Ages.

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Mind & Consciousness Explo

What is mind? What is consciousness? There seems to be no single answer that explains the phenomenon of mind. The contemporary views of philosophy, psychology, neuroscience, and cybernetics all come up with different interpretations of mind and consciousness.

It is a bit ironic that something we claim to possess is so hard to explain. Obviously mind cannot be an object of itself. Or can it? If we should one day understand the chemical and electrical processes in the brain completely, would this explain mind? Would this understanding account for all faculties including intelligence, consciousness, emotion, and volition?

On the following pages we will try to give some possible answers to this question. On the topic of consciousness, the British psychologist Stuart Sutherland once wrote: "Consciousness is a fascinating but elusive phenomenon; it is impossible to specify what it is, what it does, or why it evolved. Nothing worth reading has been written on it." - Hopefully this won’t keep you from reading on.

Epistemology and psychology.

The investigation of mind is closely related to the field of epistemology, the part of philosophy that deals with knowledge and whose principal question is: "What can we know?" Epistemology is not so much preoccupied with the process of accumulating knowledge, but with the validity of knowledge and how we can achieve certainty about it. It includes the branch of philosophy that the ancients called logic, which deals with language and thought. Bertrand Russell once remarked tellingly that the theory of knowledge is a product of doubt. Things seem to speak in favour of Russell's view – most philosophers find it easier to determine what we cannot know rather than what we can know. Perhaps the theory of knowledge should then be called "theory of ignorance."

The other question about knowledge is: "How do we know?" This question pertains to the mechanics of sensation, perception, cognition, memory, and physical brain processes. It also touches upon language and thought, but it takes a more scientific approach to these issues. The latter question is primarily asked by psychologists and neuroscientists, although philosophers recently took a renewed interest in the workings of the brain. Since both approaches are beneficial in their own way, we shall not limit ourselves to a particular one.

Defining mind.

On the surface, the attempt to define mind seems superfluous, since it is so fundamental to us. However, the explicit verbalisation of an intuitive understanding of mind is fairly difficult, because it requires us to transform the subjective first-person experience into an objective third-person description.

The American Heritage Dictionary of the English Language defines mind as follows: "The collective conscious and unconscious processes in a sentient organism that direct and influence mental and physical behaviour." This definition attributes mind to sentient organisms and identifies it with processes that control behaviour. According to the view of contemporary science, these are brain and nerve processes, cognition, motor, and sensory processes.

The faculties of mind.

The scientific definition is in agreement with the physicalist view of mind that equates mental phenomena with neuronal activity. The definition is also in agreement with the

functionalist view of psychology, which frequently divides mind into distinct faculties (as shown on the right) and then investigates those faculties individually. Some of these functions can be mapped to particular brain areas.

Dividing mind into faculties involves a great deal of abstraction, because in reality there are no clear boundaries between them. For example, the simple process of catching a ball involves sensation, cognition, and reasoning processes without there being a clear separation between the single actions of seeing the ball, calculating its speed and angle, and coordinating body movements.

Another more serious problem is that the scientific definition makes no reference to conscious experience and its subjective qualities. It is not easy to see how the experience of sensations and feelings could be part of the physical world. For example, how can emotions, such as love (affection, attraction) and hate (aversion, repulsion) which we seem to share with some animals, be described in terms of physical structures and processes?

Is the scientific definition viable in philosophy?

Perhaps it is necessary to ask whether science is capable of explaining mind at all.

Unfortunately the scientific definition falls short of one important quality: spirit. The scientific view is difficult to apply, for instance, in the context of sociology where we speak of the mental qualities of a group or population (the nation's mind, group mind, team spirit). It is also difficult to apply in the context of religion, where mind and spirit are associated with transcendental concepts such as the immortal soul, the world mind, the holy spirit, etc.

The materialist notion of mind is possibly too limited for a general philosophical discourse. It would be extremely difficult to discuss topics that involve metaphysical, ontological, and phenomenological accounts of mind. A purely materialist understanding of mind would simply evade these topics. More exotic fields of knowledge, such as theology, religion, and parapsychology do not harmonise with the scientific view of mind either. Hence, we shall postpone further attempts to define mind and as yet allow the largest possible meaning of the word, perhaps in the sense of the German word "Geist", which means both mind and spirit.

Philosophy of mind.

The philosophy of mind is the branch of philosophy that deals with mind and consciousness. It falls outside the four classical branches, metaphysics, epistemology, ethics, and aesthetics, but it relates especially to the first two. The ancients did not see it as a separate discipline, although the systematic investigation of certain aspects of mind began with the study of reason in Plato and Aristotle. During the middle ages, the philosophy of mind lingered within the confines of Christian epistemology. Important theoretical advances began to take shape only in the 17th century with Descartes and Hobbes. The philosophy of mind flourished during the late 18th and 19th century (Hegel, Darwin, Wundt, James) just before it spawned psychology, while the philosophical currents of the time flowed into the schools of phenomenology and existentialism. Psychology has ruled the field for some time during the 20th century, however, the philosophy of mind experienced a small renaissance lately due to the appearance of computer technology and other new disciplines such as cybernetics and the neurosciences. These developments brought up the question whether a machine can emulate mind and whether it can become conscious.

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550 BC - Pythagoras - the mathematical mind.

Pythagoras (582-500 BC) suggested that matter and mind are mystically connected. Logic, numbers, spirit, and soul were expressions of the same reality. He thought the soul to be immortal and wandering on a path of transmigration from one body to another. The Pythagoreans had a geometrical conception of the world. They believed that mind is attuned to the processes of nature, in particular to the laws of mathematics. Mathematics is seen as the true essence of mind.

450 BC - Anaxagoras - the universal intelligence.

Anaxagoras (500-428 BC) introduced the concept of "Nous" (mind, reason) into Greek philosophy. Nous, the eternal mind, transforms chaos into order and through it the material world comes into being. The primordial One produces forms of multiplicity through dichotomisation. This process is originated and controlled by the power of mind, or Nous. According to Anaxagoras, mind is infinite and self-organizing. It is not intermixed with anything, but pure in its being.

450 BC - Alcmaeon - the dissected brain.

The Greek physician Alcmaeon (around 450 BC) concluded from his studies of dissection that the brain is the centre of intelligence. In doing so, he contradicted the mainstream theory of his time, which held that the heart is the centre of intelligence and seat of the soul. Alcmaeon also surmised that optic nerves conduct light from the eye to the brain and that the eye itself contains light.

400 BC - Hippocrates - the four humours.

Hippocrates (460-377 BC), the founder of Western medicine, is famous for the Hippocratic oath. He invented the notion of the four humours, black bile, yellow bile, phlegm, and sanguine, which he equated with the four elements. Hippocrates thought that disease arises from an imbalance of these four humours and that people can be healed by restoring their proper proportions. The dominating humour was also thought to be responsible for the temperament (black bile = melancholy, yellow bile = bitterness and irascibility, phlegm = equanimity, and sluggishness, sanguine = passionate and cheerful).

Hippocrates correctly identified epilepsy as a brain disorder. He held that not only thought and reason, but also feelings and moods originate in the brain: "Men ought to know that from the brain, and from the brain only, arise our pleasures, joys, laughter and jests, as well as our sorrows, pains, grievances, and tears. Through it...we...think, see, hear, and distinguish the ugly from the beautiful, the bad from the good, the pleasant from the unpleasant."

400 BC - Plato - ideal forms and reason.

Plato (428-347 BC) plays an important role in the history of epistemology. His theory of ideas, which he presented in the famous cave allegory, can be seen as a precursor of both medieval realism and later idealism. Plato held that all forms of the physical world are merely instances of perfect forms in an ideal world. The idea of a table is the supreme form of table of which there is only one. It contains in itself all actual tables of the physical world. The knowledge of ideas, or supreme forms, provides intellectual and ethical guidance for humans. Plato thought that perfect forms have an actual metaphysical existence.

Plato divided the human mind into three parts: the rational part, the will, and the appetites. Ideally the will supports the rational element, which in turn controls the appetites. If the rational element is not developed, the individual behaves immorally, hence immorality is a consequence of ignorance. Furthermore, Plato distinguished

between two kinds of conscious thought: opinion and knowledge. He said that all assertions about the outside world are necessarily based on sense experience, and are therefore only opinions. In contrast, he described knowledge as a higher form of awareness, because it is gained from reason rather than from sense experience.

350 BC - Aristotle - the three souls.

Aristotle (384-322 BC) equated mind with reason and thought it to be a property of the living soul. In contrast to Plato, who believed that body and soul are two different entities, he held that mind and body are intertwined in all living beings and are thus inseparable. Growth, purpose and direction are therefore built into nature. Aristotle proposed three forms of soul: 1. the vegetative soul possessed by plants in that they grow and decay and enjoy nutriment, but they do not have motion and sensation, 2. the animal soul which bestows animals with motion and sensation, and 3. the rational soul which is the conscious and intellectual soul peculiar to man. Each higher form possesses in full the attributes of the lower souls, which makes human beings the only possessor of all three types. Aristotle also proposed a theory of memory surmising that the processes involved in short term memory (immediate recall) differ from those involved in long-term memory.

300 BC - Herophilus - the beginning of neuroscience.

The Greek anatomist Herophilus (335-280 BC) studied the human brain and recognised it as the centre of the nervous system. He distinguished the cerebrum and cerebellum and named the brain as the source of thought. Herophilus also made the first contribution to the field of neuroscience by distinguishing between sensory and motor nerves and by performing the most thorough study of brain anatomy attempted until the Renaissance.

300 BC - Pyrrho - scepticism as a state of mind.

The founder of the Greek school of scepticism, Pyrrho (360-272), stated that human mind is incapable of attaining true knowledge of anything, because ultimate reality is incomprehensible. Therefore, there is no objective knowledge, but only opinion. The best attitude one can develop in view of this fact, is to suspend any judgment completely, to free oneself from passions, and to calm one's mind. The idea that no person's judgment is more correct than that of another goes back to the first Sophist, Protagoras, who lived around 450 BC. Pyrrho developed scepticism into a more elaborate and consistent system of thought.

250 BC - Erasistratus - the brain and the vital spirit.

Erasistratus (300-260 BC) was an anatomist who worked one century after Aristotle. He found three tubular structures going to every organ of the body: an artery, a vein, and a nerve. He expanded Herophilus's theory of motor and sensory nerves by adding the thesis that all nerves are connected to and controlled by the brain. Erasistratus saw the

brain as a mechanism for distilling the pneuma (the vital spirit), which he thought was flowing from the heart up to the brain and then down to the organs.

150 AD - Galen - the great Greek doctor.

Galen (129-199 AD) was the most influential physician of antiquity, after Hippocrates. He influenced medicine profoundly until about the 17th century. Galen synthesised the thought of Pythagoras, Plato and Aristotle and built upon the discoveries of Hippocrates and Erasistratus. He proved that the arteries carry blood instead of air (as the Greeks formerly presumed); and he demonstrated that the brain controls motion and voice. Galen further assigned the three largest organs of the body to be the seat of the three Aristotelian souls; the liver as the seat of the vegetative soul, the heart as the seat of the animal soul, and the brain as the seat of the rational soul.

For Galen, the rational soul was divided into the faculties of imagination, reason, and memory. He located these three faculties in the ventricles of the brain. Because the function of the brain was to distribute animal spirit throughout the body, to Galen it seemed that the fluid filled ventricles perform this function and thus disregarded the white and grey matter surrounding the ventricles. According to Galen, the brain receives vital spirit (pneuma) from the heart, which is mixed into the sanguine humour (blood). The brain then separates the animal spirit out and stores it in the ventricles, from where it is distributed throughout the body via the nerves. This mechanism of circulating pneuma controls muscles, organs, and all of the body's activities.

250 AD - Plotinus - the emanation of mind from the Absolute.

Plotinus (204-270 AD) rejected Aristotle's notion of the soul not being able to exist without the body. Building mainly on Plato, he said that mind is a prisoner of the body. Plotinus held that soul is the immortal part of mind. It survives the death of the body and enters a series of transmigration from one body to another. Consequently, the soul is the only abiding reality of the human condition. Plotinus formulated a theory of emanation according to which mind emanates originally from the Absolute Being, or the One, and then forms Nous, the universal intelligence, from which the world spirit is formed in turn. Human mind, animal mind, vegetative mind, and finally matter all emanate from the world spirit. They are different manifestations of one universal intelligence.

400 AD - St. Augustine - the illuminated mind.

The church father St. Augustine (354-? AD) had an interesting idea about mind. He said that the human mind couldn't gain knowledge from sense perception alone. He also rejected Plato's theory of ideas. Instead, according to Augustine, knowledge is acquired on account of divine illumination. He argued as follows: The shape of an object such as a tree can only be seen by the eye, because the object is bathed in light. Similarly the mind can only recognise truths, such as the mathematical truth 1+1=2, because it is illuminated by the light of eternal reason. This light is not so much the source of ideas and knowledge, but the condition under which mind is able to recognise the quality of truth. In spite of the simplicity of this idea, or perhaps due to it, Augustine had a tremendous influence on the philosophers and theologians of the Middle Ages.

The brain is probably the most amazing physical structure we know. Nowhere else in the universe do we find anything comparable. People have tried to understand it for thousands of years. The ancient Greeks thought that it acts like a radiator cooling the blood. Medieval philosophers believed that it is the abode of the soul and that it could be invaded by spirits. Today, we think that the brain is responsible for all faculties of mind. The human brain is one of the most intensively researched items in biology, yet there are many questions to which we don’t have answers. For example, we don’t know how consciousness arises from the brain. Nevertheless, significant advances were made in brain research during the past few decades. From classical neuroanatomy we know the different parts and structures of the brain. From neuropsychology we know their psychological and behavioural functions. From neurophysiology and neurochemistry we know the workings of neurons (brain cells) and their connections.

You may find that the appearance of the human brain is quite unimposing. It doesn’t really look like one of the world’s wonders, but rather like something you might find washed up on a beach. The human brain is the size of a large grapefruit and weighs 1 – 1.5 kg. The outer visible layer, the cortex, is part of the cerebrum. It comprises two halves, or hemispheres, of highly wrinkled grey matter. The grey matter consists of the

cell bodies of neurons, whereas the subjacent white matter consists of nerve fibres (axons) that constitute long distance connections between neurons. The two hemispheres are separated by a deep grove, the longitudinal cerebral fissure. They are connected at the base by the corpus callosum, a thick layer of nerve fibres. At the outer sides of the hemispheres there is another deep grove, the lateral fissure or lateral sulcus, which divides the frontal and parietal lobes from the temporal lobes. Developmentally, the brain can be divided into three main divisions, the hindbrain (rhombencephalon), midbrain (mesencephalon), and forebrain (prosencephalon).

Divisions of the brain.

The three main parts of the brain can be further divided into substructures, as shown in the illustrations. We will first look at these parts from an evolutionary point of view. The brain stem is the oldest part of the brain. It contains the midbrain and the hindbrain minus the cerebellum. It evolved more than 500 million years ago. Because it resembles the brain of a reptile, it is also called the "reptilian brain". The brainstem controls autonomic functions, such as breathing, heart rate, and digestion. The cerebellum, or "little brain", which is attached to the back of the brainstem, is likewise evolutionary ancient. It contains circuits which are similar in all vertebrates, including fish. Its function is to control and adjust posture and to coordinate muscular movement. The expanded human cerebellum also has a role in some cognitive functions, such as attention.

The limbic system is the group of structures located between the brain stem and the cortex. It evolved between 300 and 200 million years ago and –since it is most highly developed in mammals– it is also called the "mammalian brain". The limbic system is involved in emotion and motivation. For example, the amygdala is involved in aggression and fear, the hypothalamus is involved in sexual arousal, and the nucleus accumbens, the brain’s pleasure centre, is involved in reward, pleasure, and addiction. Furthermore the limbic system controls a host of different functions, including heart rate and blood pressure, hunger, thirst, the sleep and wake cycle, memory formation, and decision making. The two key parts of the limbic system are the hypothalamus and the pituitary gland, the "master gland" of the body. The limbic system interacts with the body through the endocrine system and the autonomic nervous systems. Finally, there is the cerebrum, the largest part of the forebrain, which is evolutionary the most recent and also the largest part of the brain. While the forebrain of a frog is a mere bump, it balloons into the large structure of the cerebrum in higher animals covering the brain

stem and the limbic system like the head of a mushroom. The most outstanding feature of the cerebrum is the cortex, which is about two millimetres thick and, like a walnut, possesses an intricately folded surface. This is a special characteristic of "higher" mammals. The many grooves (sulci) and ridges (gyri) create a large surface area of 1,5 square metres allowing for maximum packing of neurons. The cortex is involved in many high-level functions, such as visual and verbal symbol processing, perceptual awareness, communication, language, understanding, and rational thought.

Divisions of the cortex.

The cerebral cortex evolved in three stages and the resulting parts are called archicortex, paleocortex, and neocortex. The most recent one is the neocortex which occupies the topmost layer of the cortex; it is especially developed in humans. Generally, the cerebral cortex acts as a processor of sensory input information, which it receives via the thalamus. The cortex of each hemisphere can be divided into several different areas which are called lobes. At the rear of each hemisphere, the occipital lobe deals primarily with vision, hence, it is also called the visual cortex. It processes visual information transmitted from the eye and analyses it for movement, orientation, and position. A person can become blind if the occipital lobe is damaged, even while the eyes and optic nerves remain intact.

The temporal lobes, located at the outer sides of the hemispheres near the temples, have a number of different functions. A part of it is responsible for hearing. This part is called the auditory cortex. The auditory cortex sits at the lateral fissure and has the size of a large coin. The adjacent areas are involved in high-level auditory processing, such as language perception. Wernicke’s area, which is located at the junction of the temporal and parietal lobe, is mainly responsible for the comprehension of spoken language. Additional temporal lobe functions include behavioural expression, the recognition of faces and scenes, as well as episodic and declarative memory, i.e. the memory and retrieval of events and facts as in textbook learning. Damage to the temporal lobes can cause aphasia, the loss of the ability to form and comprehend language. Damage to the right temporal lobe can result in impaired performance of spatial tasks, for example the ability to draw. If the temporal lobe is electrically stimulated, some persons report being present at two places at the same time. They are conscious of the present moment, as well as of another event stored in memory. For example, they might feel they are at the same time in the kitchen of their home, cooking a meal.

The parietal lobe is a relatively large area located at the back of the hemisphere just above the occipital lobe. Much less is known about this lobe than about the other three lobes. It is involved in touch, pain, and taste sensation, visual and spatial perception, and body orientation. It seems that the parietal lobe is where we put our world together. The parietal lobe integrates visual information and constructs maps and coordinate systems that represent how we see the environment. Another function of the parietal lobes is to combine letters into words, and words into sentences. Damage to the left parietal lobe can lead to Gerstmann’s syndrome which includes the confusion of left and right, impairment of with writing (aphasia) and calculation abilities (acalculia), and difficulty with recognising body parts (agnosia). Damage to the right parietal lobe can result in difficulties with spatial perception, such as unilateral neglect, the limited conscious awareness of information coming from one side of the body, and constructional apraxia, the inability to draw or construct simple configurations.

The frontal lobe, just behind the forehead, is the largest of the four cortical lobes. It controls much of the rest of the brain’s functions. In particular, it is responsible for the higher functions, such as reasoning, planning, organising, problem solving, selective attention, and personality. The frontal lobe is highly connected to the limbic system, which suggests that it is involved in emotions. Moreover, it plays a key role in memory, language processing, speech production, and movement. Cognitive maturity in adulthood is associated with the maturation of cerebral fibres in the frontal lobe. The frontal lobe contains a great number of dopamine-sensitive neurons, which are linked to pleasure, motivation, attention, problem solving and long-term memory. Broca’s area, located at the base of the frontal lobe just above the parietal lobe, is thought to be responsible for the production of speech. Brain damage to this area causes expressive aphasia, the inability to form sentences. If the frontal lobes are damaged, the individual may show symptoms of dementia, such as becoming incapable of planning and executing, incapable of comprehending situations and ideas, unable to focus attention, and being distracted by irrelevant stimuli. Other symptoms include impairment of short-term memory, lack of inhibition, and difficulty in learning new information.

The primary motor cortex is located in the precentral gyrus of the frontal lobe, running from the longitudinal fissure at the top of the brain down to the lateral fissure. It controls movements of specific body parts. Electrical stimulation of certain areas of the motor cortex results in movement of the associated body part. From top to bottom, these

are feet, legs, hip, trunk, elbows, hands, and face. The areas are not represented in proportion to the size of these body parts. For instance, the areas for the hand and its individual fingers, as well as the area of the face and its different parts are larger than the areas for other body parts. The primary motor cortex receives feedback from the primary somatosensory cortex to which it is intricately linked. The primary somatosensory cortex, located in the postcentral gyrus behind the primary motor cortex, is the main sensory receptive area for the sense of touch. These two areas wok in conjunction with the secondary motor cortex, located before to the primary motor cortex, which prepares movements and combines series of movements into coordinated sequences. Damage to the primary motor cortex disrupts the ability to move one body part (e.g. one finger) independently of another. It can also reduce the speed and accuracy of movements, but it does not cause paralysis.

Lateralisation and the split brain.

The two hemispheres of the cerebrum look almost identical, but at closer inspection we find significant differences. In 1836, a virtually unknown French country doctor found that all of his brain-damaged patients with speech problems suffered injuries to the left side of the brain. This early finding anticipated modern research of brain lateralisation. Clinical evidence suggests that the two sides of the cerebrum serve different functions. Injuries to the left side usually impairs reading, writing, speaking, calculation, and understanding. Injuries to the right side have less dramatic effects, but tend to affect spatial perception and movement. More extensive research has shown that the left and right hemisphere’s involvement in certain functions is disproportionate.

Left Side Dominance General Function Right Side Dominance

WordsLetters

VisionGeometric PatternsFacesEmotional Expression

Language Sounds AuditionNon-language SoundsMusic

Touch Tactual Patterns (Braille)Complex Movement Movement Spatial Movement PatternsVerbal Memory Memory Nonverbal MemorySpeechReadingWritingArithmetic

Language Emotional Content

Spatial Ability

GeometryDirectionDistanceMental Rotation of Shapes

Yet, it would be wrong to speak of compartmentalisation. The hemispheres of the brain work in tandem as a complex whole. In a famous experiment in the 1950s, the American neuropsychologist Roger Sperry separated the corpus callosum, to treat epileptics. The corpus callosum is a strand of approx. 200 million nerve fibres connecting the left and right hemispheres, which the brain uses to transfer signals between the hemispheres. The patients remained largely normal, but each hemisphere

worked independently. Human split brain patients seemed to have two independent brains, each with its own abilities, memories, and emotions. Notably, the left hemisphere of split brain patients was capable of speech, whereas the right hemisphere was not.

[ Read On ]

Although the structure and organisation of the brain seems highly complicated, all the different parts boil down to the same fundamental building block: the neuron. The neuron is a special type of cell which processes and transmits information by electrochemical means. Neurons are found in the brain, the spinal chord, and in the nerves of the peripheral nervous system. They come in a great variety of shapes and sizes, however, most of them look like the one in the illustration below. Neurons are tiny. The cell body (soma) has a diameter of only 10-25 micrometres, which is just a little bit more than its cell nucleus. Their quantity, however, is immense. The human brain has roughly 100 billion neurons, each of them having several thousand connections to other neurons. This comes up to a whopping total of 500-1000 trillion connections within the brain. No computer on earth has that many connections or such a massively parallel organisation. At any rate, the often cited brain-computer analogy is inept. Nervous systems are a far cry from the simple feed forward input/output circuits of a contemporary computer. Unlike a computer, the brain is a living thing; it can grow and change; and the processes of neural conduction is much more complex than signal conduction in the logical gates of a computer chip.

Neurons, or nerve cells, are eukaryotic cells which resemble all other cells in the human body with one exception. They are specialised in conducting information. The neuron has several fundamental characteristics. It has an excitable membrane which allows it to generate or propagate electrical signals, a tree of dendrites which receive signals, and an axon that transmits signals. The axon is a cable-like fibre that transmits nerve impulses from the neuron to other neurons. Axons are only about one micrometre across, but they can become extremely long. For instance, the axons of the sciatic nerve in the human body may run a metre or longer from the spine to the toes. This could be compared to a 50 cm calibre pipeline that runs 2000 km long. A layer of fatty cells, the myelin sheath

punctuated by the unsheathed nodes of Ranvier, insulates the axons of some neurons and speeds the impulses. Each neuron has only one axon which usually branches out extensively and passes signals to multiple target cells. Terminal buttons at the end of each axon branch connect the neuron to the receiver cells via synapses. Thus the synapse provides the functional connection between different cells. It consists of the target area, which may be a spine, a dendrite, or a cell body, and the synaptic gap between the axon terminal and the receiver cell. The dendrites are a branching arbour of cell projections that receive signals from terminal buttons which they conduct to the cell body.

Neural conduction

The principle of neural conduction can be described by neural impulses and synaptic transmission. These are two complementary methods of conduction which neurons are capable of. The neural impulse is either on or off, whereas synaptic conduction –based on the transmission of chemicals– is gradual. This can be likened to digital and analogue signal conduction. A neuron fires an impulse when it is stimulated by chemical messages from connected neurons, or by pressure, heat, or light. This impulse, called action potential, is caused by the depolarisation of the membrane potential of an excitable cell. Normally an electrical potential exists between the inside and outside of the cell. When ion channels in the cell membrane open, the exchange of ionised

elements through the open channels causes an electric discharge. This impulse travels through the cell membrane and the axon hillock down to the axon and is then carried away from the cell. It propagates through the body at a speed of 10-100 metre per second, depending on the type of axon. The impulse doesn’t travel like an electrical signal, but rather through successive depolarisation of adjacent areas of the axon membrane, much like falling dominoes. During a very brief resting pause, the neuron pumps positively charged atoms back outside the membrane, after which the neuron is ready to fire again. This electrochemical process can be repeated 100 times per second.

Synaptic transmission is different. There are two type of synapses, electrical and chemical synapses. Electrical synapses couple neurons electrically via gap junctions. Chemical synapses work through the exchange of special chemicals called neurotransmitters. There are some 75 known neurotransmitters which amplify, relay, or modulate signals between neurons and other cells. These substances are produced by the soma, the chemical factory inside the neuron. The neurotransmitter molecules are usually packaged in spherical vesicles. These vesicles are conveyed through the axon towards the terminal buttons through special channels called microtubules, which are tiny pipelines running inside the axon. When a neural impulse reaches the knob-like terminals of the axon it triggers a biochemical cascade which causes the vesicles to fuse with the presynaptic membrane and release their neurotransmitters. The neurotransmitter molecules then cross the synaptic gap from the presynaptic membrane to the postsynaptic membrane within 1/10,000th of a second. It is like a very brief rain shower of neurotransmitters. Receptors on the postsynaptic membrane bind the neurotransmitter molecules. For a very brief period, ion channels on the postsynaptic membrane open to allow ions to rush in or out. This causes the transmembrane potential of the receiver cell to change. There are two types of changes. Depolarisation causes an excitatory postsynaptic potential; hyperpolarisation causes an inhibitory potential.

With this knowledge we can understand how neurons work together in the brain. Neuron A fires and reaches neuron B via the synapse AB. If the postsynaptic potential is excitatory and if it is strong enough to reach the action potential threshold, then neuron B fires. Synaptic strength is defined by the change in the transmembrane potential. If the potential does not reach the threshold value, neuron B might still fire if it simultaneously receives excitatory messages from other synapses. Thus multiple weak excitation can also trigger a postsynaptic action potential. On the other hand, neuron B might receive inhibitory messages from other synapses. In this case, neuron B might not

fire, even if it receives a excitatory potential from a strong synapse. Thus a single neuron behaves a bit like a relay. This relatively simple behaviour lies at the root of neural firing patterns. The neuron’s status is either on or off, i.e. firing, or at rest. The complexity of neural firing patterns arises from the nature of synaptic connections. There is one thing we forgot to mention, however. What happens to the neurotransmitters after they are left in the synaptic gap? Obviously, multiple neurotransmitter releases from the terminal buttons would eventually accumulate and clog the synapse. However, this does not happen. There are two mechanisms that terminate synaptic transmission: reuptake and enzymatic degradation. The majority of neurotransmitters are almost immediately drawn back into the presynaptic buttons after release. There they are repackaged into vesicles and then recycled. This mechanism is known as reuptake. Other neurotransmitters are broken apart by enzymes after transmission and are thus deactivated.

Neurotransmitters and brain chemistry

Neurotransmitters are messenger substances. They can be classified into five different types of substances: amino acids, monoamines, neuropeptides, acetylcholine, and soluble gases. Amino acids are the most common neurotransmitters. Among them are glutamic acid and gamma-aminobutyric acid (GABA), which are the principal neurotransmitters in the human brain. Other well-known substances include noradrenalin, dopamine, and serotonin, which belong to the group of monoamines. Glutamate is the most prevalent excitatory neurotransmitter in the mammalian central nervous system, and GABA is the most prevalent inhibitory neurotransmitter. A neurotransmitter produces either excitation or inhibition. Only in rare cases, where the effect is dependent upon the receptor subtype, a neurotransmitter causes both inhibition and excitation. The receptor is the protein molecule in the postsynaptic cell that binds the neurotransmitter and initiates a reaction. Once again, there are different types of receptors, such as ion-channel linked receptors, chemically activated ion channels, and G-protein linked receptors. To simplify things, we can imagine neurotransmitters as keys to certain receptor locks, which –once unlocked– initiate an excitatory/inhibitory process in the postsynaptic cell.

Acetylcholine

Acetylcholine (ACh) is the messenger at junctions between motor neurons and muscle cells. When ACh is released to muscle cells, the muscle contracts. If ACh release is blocked, the muscle cannot contract. Curare, the poison used by South American Indians for hunting with darts, blocks ACh receptors and thus paralyses the victim. Curare leads to death through suffocation, because the victim cannot contract the respiratory muscles anymore. By contrast, the neurotoxin of the black widow spider triggers a synaptic flooding of ACh, and thus causes painful contractions, convulsions, and possible death.

Glutamic acid and GABA

Glutamic acid (glutamate) and Gamma-aminobutyric acid (GABA) are the excitatory and inhibitory workhorse neurotransmitters of the nervous system. It is believed that glutamic acid is involved in cognitive functions, such as memorising and learning, because of its role in synaptic plasticity. Glutamic acid overstimulation is associated

with diseases like amyotrophic lateral sclerosis, lathyrism, and Alzheimer's disease. Glutamic acid excess can cause neuronal damage and eventual cell death. Glutamic acid is also the precursor of GABA which is synthesised with the help of an enzyme whereby the excitatory neurotransmitter is converted into an inhibitory one.

Dopamine

Dopamine is crucial to physical and mental health. It has a role in movement, cognition, pleasure, and motivation. Neurons containing the neurotransmitter dopamine are clustered in the midbrain in an area called the substantia nigra. A shortage of dopamine and the death of dopamine neurons causes Parkinson’s disease which is associated with depression and the loss of control of movement. Dopamine in the frontal lobe regulates the information flow from other areas of the brain which is vital to memory, attention, and problem solving. Dopamin depletion in the prefrontal cortex is associated with attention deficit disorder and schizophrenia. Disruptions of the dopamine system are also linked with psychosis. However, the most recognised role of dopamine in the brain is providing pleasure and enjoyment, hence, dopamine has also been termed the "reward chemical". Dopamine is released in the course of rewarding experiences such as food, sex, and other stimulating experiences.

Epinephrine and norepinephrine

Epinephrine (adrenaline) and norepinephrine (noradrenaline) are the body’s stress hormones which are typically involved in fight-or-flight situations. Epinephrine and norepinephrine are released into the bloodstream from the ardrenal medulla. The secretion of these substances is the physiological response to a threatening or exciting situation. Environmental stressors (such as bright lights, piercing noise, etc.) also cause release. The two substances are structurally very similar and they function both as neurotransmitters and hormones. As neurotransmitters they mediate chemical communication in the sympathetic nervous system, a branch of the autonomic nervous system. Among the major effects mediated by epinephrine and norepinephrine are increased heart rate, blood vessel constriction and increased arterial blood pressure, dilation of bronchioles assisting in pulmonary ventilation, stimulation of the fat burning process, dilation of pupils, increase of metabolic rate and muscle readiness, and inhibition of non-essential function, such as digestion.

Serotonin

Serotonin is an important neurotransmitter synthesised by so-called serotonergic neurons in the brainstem. The serotonin system is the largest single system in the brain, influencing a broad range of basic functions. Serotonin is important, because it plays a key role in the regulation of mood, sleep, appetite, vomiting, and sexuality, and because it is associated with a host of mental disorders, such as depression, bipolar disorder, and anxiety. Serotonin differs from other neurotransmitters in one respect. It is able to modulate the effect of other neurotransmitters, making it effectively a "master" neurotransmitter. Serotonin is known to unlock 14 or more different receptor subtypes, each of which has a distinct function in regulating impulses, motivation, moods, and appetite. Low moods and low motivation are associated with low serotonin levels. There are antidepressants on the market, e.g. Prozac, Zoloft, and Paxil, which act as serotonin reuptake inhibitors and thus increase the availability of serotonin in the brain. Other

medications increase the serotonin reuptake and reduce serotonin levels. These medications are used to aid or tweak an imbalanced serotonin system.

Many regard consciousness as the final frontier of science. Although science has produced a great deal of knowledge about the brain and the nervous system, it did not (yet) produce a viable theory of consciousness. There is the seemingly intractable problem that consciousness cannot be measured, detected, or quantified in any way. To further complicate things, consciousness is about inner (first-person) experience and its subjective qualities, whereas science relies on ideas and experiences that can be observed and verified by third parties. The investigation of inner phenomena involves subjective, idiothetic accounts, whereas the investigation of outer phenomena involves objective, verifiable accounts. It would seem that the scientific method, which relies on repeatable experiments to test a hypothesis, reaches its limits when dealing with consciousness. One must therefore ask whether science is able to explain consciousness at all.

Scientists have responded to these problems in two ways. One group claims that consciousness is not a scientific concept to begin with, that its is too vague, and that claims involving consciousness are unverifiable. This position was taken to the extreme by the 20th century behaviourist movement, which simply ignores consciousness. It tends to see the mind as a hypothetical construct, disregarding internal states entirely, only considering external states (behaviour). The other group of scientists acknowledges the existence of internal conscious states and claims that these can be fully explained by neuroscience. There is a variety of such views, known as materialism, reductionism, functionalism, and biological naturalism. Some proponents of these views assert that consciousness is a “bag of tricks” (Dennett) and that -by and large- it has already been explained by neuroscience.

But perhaps this is jumping to conclusions. Science postulates a materialist understanding of consciousness, but there are significant gaps in this understanding. The materialist view occasionally appears like that of the mythical tribesman who discovered a TV set. Although ignorant of the existence of radio waves, he is confident that he understands the origin of the voices and images in the TV. After he has carefully disassembled the TV, he is able to demonstrate that applying a voltage to certain points

produces an audible noise in the speaker, or a dot of light on the screen. He has even worked out how the electron beam can be modulated to create a matrix of dots. On account of these discoveries, he triumphantly declares that the voices and pictures are produced inside the electronic circuits of the TV set and that the operating principle of the TV set can be explained without invoking “supernatural” radio waves. Yet, his fellow tribesmen are not quite satisfied with this explanation. It seems too mechanical to them and they keep wondering why the voices and images in the TV set appear so real. The tribal scientist justifies himself: “We have not worked out all the details yet, but we understand the principle.”

This situation is perhaps analogous to present day consciousness research. Mainstream scientists and philosophers believe that consciousness is based on and produced by the brain. This might be compared to the idea that TV images and sounds are produced inside the TV set. Obviously, in case of the TV set, it is only half the truth. The TV images and sounds are neither local to the TV set, nor do they have a life of their own. They are produced elsewhere and transmitted by radio waves. We all know that a TVs have an antenna and a receiver that pick up radio waves and translate them into voltages to generate images and sounds.

What if the brain and nervous system relate to consciousness like the TV set to radio signals? Let's call this the nonlocal model of consciousness. If we accept the nonlocal model of consciousness provisionally, we can compare TV reception to sense perception. We can compare qualia (conscious experience) to TV images and sounds; we can compare memories to the recording function, thoughts to the playback and edit functions, and mental chatter to audiovisual noise. Furthermore, if the nervous system/brain functions as receiver/modulator of consciousness rather than its producer, it follows that consciousness is not based on the brain, but that the brain is based on consciousness. There are a number of theoretical considerations and phenomena that point in this direction. These phenomena show the limits of the current mainstream (materialistic) understanding of consciousness and provide theoretical support for the nonlocal model of consciousness. In the remainder of this section, we will look at five such points: a) the epistemic gap in materialism, b) the absence of a neural correlate of consciousness, c) out-of-body experiences (OBEs), d) near-death experiences (NDEs), and e) the measurement problem in quantum physics.

The epistemic gap

The epistemic gap, also known was the explanatory gap, is the gaping hole in materialist ontology. It is the failure to explain how something immaterial, such as conscious experience, arises from something material, such as the brain. The epistemic gap can also be phrased as follows: How does subjective experience arise from electrochemical processes in the brain? Subjective experience -or qualia- seems to be entirely nonphysical. No scientist has managed to explain how qualia arise and why they arise. After all, we can perfectly well imagine an organism responding to external signals and stimuli without being conscious of them. Materialism offers two different approaches to deal with the “problem” of mind: reductionism and emergentism. Reductionism argues that it is principally possible to reduce higher-order systems to lower-order systems. It postulates that mind is a higher-order system that can be reduced -in principle- to the biological system of the human brain and body. The biological system can in turn be reduced to chemistry, which can again be reduced to physics. Therefore -according to

reductionism- mind is ultimately physical. The problem with this approach is that reductionism cannot point out the causal relationships involved in each step of the reduction. On this account, reductionism fails.

The non-reductionist approach -known as emergentism- holds that the higher-order system emerges from the lower-order system on account of supervenience. The concept of supervenience is defined as follows: A set of properties A is said to supervene upon another set B if no two things can differ with respect to A-properties without also differing with respect to their B-properties. In other words, any difference in the higher-order system implies a difference in the lower order-system. It is said that mind supervenes on the biological system and that mind displays new emergent properties which are not intrinsic to the underlying system. Upon closer inspection, we find that emergentism suffers from the same problem as reductionism. It fails to account for the causal relationships between higher and lower order systems. Supervenience cannot explain why properties are related as they appear. Hence, invoking supervenience is a bit like appealing to magic. It is not an explanation at all. This strongly suggests that the epistemic gap cannot be bridged by materialism.

Absence of a neural correlate of consciousness

The French philosopher René Descartes held that the soul was located in the pineal gland and that consciousness emanates from it. This is often cited as the first attempt to relate consciousness to a biological structure. While the study of the brain can be traced back to ancient Egypt, modern neuroscience began in the latter half of the 20th century. Since then, neuroscientific research has produced a massive amount of data and knowledge about the brain which is still growing at a fascinating pace. One of the goals of neuroscience is to correlate mental states with biophysical states, systems and processes in the brain. This effort has only partly been successful. For example, we can correlate the capacity of speech to the Wernicke and Broca areas. We can correlate motor action to the motor cortex, vision to the optical nerve and the visual cortex, certain feelings such as arousal, pleasure, and excitement to neurotransmitters.

However, the search for the neural correlate of consciousness has come up empty. Decades of research did not produce what was originally envisioned by neuroscientists – the correlate or substrate of phenomenal consciousness. At the beginning of the 21st century, conscious experience remains as enigmatic as ever. This is not to say that it eludes neuroscience completely. Many epiphenomena of conscious experience -from brainwaves and brain chemistry to neural activity- have been explored and can be matched to certain types of experience. Yet, it is phenomenal experience itself that puzzles scientists. There is no causal explanation that leads from brain states to qualia. There are no neural correlates for thought, beliefs, and ideas. In fact, most neuroscientists have given up the search for the neural correlate of conscious experience. They feel that it is the wrong approach. The absence of a neural correlate suggests that consciousness does not originate or reside in the brain at all.

Out-of-body experiences

Out-of-body experiences (OBEs) are ostensibly based on the separation of consciousness from the body. Those who experience an OBE report that they see their own body from the outside, that they float through space, and that they can penetrate

solid objects. With a prevalence of 5%-10%, OBEs are more common than generally believed. Although an OBE often occurs spontaneously, or as a consequence of body trauma, it can also be self-induced. Experienced out-of-body travellers can prolong the experience and travel at will. There are two theories about it: one says that there is something that leaves the body; the other says nothing leaves the body and that OBEs are complex hallucinations caused by non-ordinary brain states. Both theories are problematic, because the first relies on the paranormal concept of an “astral body”, and the second theory cannot account for the complexity of the experience and its veridical aspects.

There are many reports of so-called veridical OBEs. These involve correct accounts of remote objects, events, or people which are later verified by a third person. For example, the subject might report about people in another room, or things that are outside the field of vision and cannot possibly be perceived through the sense organs. Several veridical OBEs have occurred under laboratory conditions. Dr. Michael Sabom reported 32 cases of cardiac arrest patients who were able to describe their resuscitation in great detail. Dr. Pim van Lommel and Dr. Kenneth Ring have published similar studies with well over 100 cases of veridical OBEs. Dr. Charles Tart has conducted an experiment where the subject has correctly identified a 5-digit number that was placed on top of a shelf -invisible to the subject- after an OBE. Mainstream science cannot explain these findings. Veridical OBEs can be explained if we assume that consciousness is nonlocal to the brain.

Near-death experiences

Near-death experiences (NDEs) are reported by 10%-15% of all people who find themselves in a life-threatening situation due to critical surgery, cardiac arrest, an accident, or some other cause. Since most of these people end up in a hospital, the conditions for scientific study are favourable. The first case studies were published by E. Kübler-Ross, R. Moody et al in the 1970s. Since then a large amount of reports and studies with thousands of cases have been collected, more recently by B. Greyson, M. Morse, S. Parnia, P. v. Lommel and others. NDEs are conscious experiences at impending death that have recognisable features, such as a sense of well-being, love, and peace, movement through a tunnel or a passage, a bright spiritual light, meeting deceased relatives and friends and/or spiritual beings. The most astounding observation is that consciousness continues after clinical death. Recent studies have shown that these experiences can occur even when neuronal activity in the brain has ceased, so that -according to neuroscience- there should not be any conscious experience at all.

Sceptics argue that NDEs are caused by physiological processes in the dying brain. For example, they hold that the experience of a tunnel and bright light is caused by the loss of cell function in the visual system due to anoxia (lack of oxygen). However, while every patient with cardiac arrest experiences anoxia, not everyone experiences an NDE and not every NDE features a tunnel experience, which questions the causal connection. Other sceptics argue that the experience is caused by the release of dimethyltryptamine (DMT) or endorphines in the brain. Again, DMT release does not necessarily result in an NDE. DMT is also released at night time during sleep, though in smaller quantities, and it does not have the life-changing effect that NDEs are known for. Furthermore, if NDEs were a drug-induced, one would expect the experience to have personal random contents, much like a dream or an LSD trip. Reports of congenitally blind people who

were suddenly able to experience vision in an NDE make biological explanations even harder. So far, there is no coherent physiological explanation for the NDE phenomenon.

Dr. Pim Van Lommel writes in his paper About The Continuity Of Our Consciousness: “According to our concept, grounded on the reported aspects of consciousness experienced during cardiac arrest, we can conclude that our consciousness could be based on fields of information, consisting of waves, and that it originates in the phase-space. […] Such understanding fundamentally changes one’s opinion about death, because of the almost unavoidable conclusion that at the time of physical death consciousness will continue to be experienced in another dimension, in an invisible and immaterial world, the phase-space, in which all past, present and future is enclosed. Research on NDE cannot give us the irrefutable scientific proof of this conclusion, because people with an NDE did not quite die, but they all were very, very close to death, without a functioning brain.”

Measurement problem in quantum mechanics

In short, the measurement problem in quantum mechanics is the problem how and why Schrödinger's wave function collapses upon measurement. The word “collapse” describes a transition from a superposition of different states of a particle, as described by Schrödinger's wave function, to a single state upon interaction. The measurement of physical quantum system always results in a definite state, whereas the wave function describes the evolution of the same system as a multitude of superposed states, each with a certain probability. In abstract terms, the wave function collapse describes the reduction of a system of potentialities to a single definite state. Since it is impossible to observe the collapse directly, a number of different interpretations exist. These interpretations revolve around several key questions, namely how nature behaves at the subatomic level, whether nature is deterministic or non-deterministic, and whether the observer plays a causal role in the wave function collapse.

The Copenhagen interpretation is one of the more popular interpretations of the measurement problem. It was first formulated by Heisenberg and Bohr in the 1920s, and it became later synonymous with indeterminism and Bohr's correspondence principle. Today, there are several variations of this interpretation. Since it asserts collapse upon measurement, one particular version of the Copenhagen interpretation posits that collapse is caused by a conscious observer, which implies that consciousness plays a participatory role in the measurement. Hence, it is called the Participatory Anthropic Principle (PAP), following J.A. Wheeler's Anthropic Principle. While PAP is considered speculative, many scientists feel that the classical paradigm of a separate observer can be questioned and that the role of consciousness needs to be reevaluated in view of quantum mechanics. The idea of consciousness interacting non-locally with physical systems could therefore be an important element in understanding how reality works at the subatomic level.

http://www.thebigview.com/mind/nonlocal.html

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Saturday, February 11, 2012

An Introduction to Presocratic Philosophy

Presocratic Greek philosophers gave us the first murmurings of Western rationalism. This is a brief outline of their most important concepts.

The Milesian Presocratics

The first “big thinkers” of the West hailed not from Athens but from a place called Miletus, a town on the Ionian coast in what is today a part of Turkey. Their preoccupation was with explaining something called phusis, the root word of terms like physics and physiology. However, they were still somewhere on the bridge between mythology and science. For these theorists, nature itself was alive in some sense.   

Thales

A top contender for the title of First Philosopher in Western History, Thales left no written documents. All that we know of him comes from Aristotle, who says that Thales observed that all things were nourished and generated by moisture. From this plain fact Thales made the generalization that all things were derived from water, and eventually they degenerated back into water. He also believed that the earth rested on a body of water. He may have gotten the answer wrong about the basic “stuff” in the universe – today we know that it is made up of atomic particles much more fundamental than water – but at least he hit upon a scientifically important idea: explaining the greatest number of observable facts with the smallest number of principles.         

Anaximander

The “big idea” for this Milesian was something called “The Boundless” (apeiron), which may also be rendered as “The Infinite” or “The Indefinite.” No shape, no form, no structure – something like an amorphous blob or primordial soup, except that it did not even have the quality of being liquid. Countless worlds came into being from out of this blob through a process of differentiation, and they all would eventually be absorbed back into it. The existence of material things resulted from an imbalance or “injustice” in the blob, where conflicting elements like moisture and dryness tried to dominate each other, but this would be corrected by the ordinance of time or fate. The celestial bodies were really great bands of fire many times the diameter of the earth; they were sheathed in mist, except for certain apertures through which the fire shone. The earth itself, which had the shape of a cylinder or drum with a depth equal to one-third its diameter, was not supported by water or any other material thing – it just “floated” in the “center” of the blob, equidistant from all of the other celestial bodies. 

Anaximenes   

This Milesian declared that “air” was the fundamental substance, by which he meant something like mist or vapor. In that sense he wasn't radically different from Thales. All material things derived from this air through the processes of condensation and rarefaction. As air grew progressively denser, in some sort of “felting” or compression process, the visible objects of nature were formed – trees, rocks, earth, etc. Unlike the modern scientific conception, this air wasn’t just “dead weight”; it was more like a “divine vapor” – an active, living substance.

Heraclitus of Ephesus

Heraclitus, who was also from Ionia, declared that the fundamental stuff was fire. The world-order (kosmos) was conceived of as a divine fire, which was never extinguished and which was alive in some way. However, this order was antecedent to the gods, so it had not been created by them. There was a cyclical transformation of elements, which started with fire and which had fire as its “currency.” All things were exchanged for fire – and fire for all things – as goods were exchanged for money and money for goods. Souls also took part in this cosmic economy. For souls, dryness was the desired state and it was “death to become water.” 

Heraclitus also thought about how opposites related to one another to form a higher unity, and in this way he was something of a departure from the “scientific” concerns of the Milesians. In other words, his concerns were a bit more logical and terminological. There was a unique divine intelligence that governed everything, and apparent opposites were just manifestations of this one logos. A tug of war between opposing forces was somehow necessary and desirable, as a string on a musical instrument could produce pleasing sounds by first being pulled in opposite directions. No tension, no music; no gravity, no dance.           

Heraclitus was fond of making puzzling statements about how it was impossible to step twice into the same river, or about how the sun was new every day, or about how everything was in flux. He was pointing out that an object, or a thing usually thought of as having a stable identity over time, was not really as stable as it appeared. We moderns are in a much better position to appreciate his insight: Today’s sun is not exactly the same collection of atoms as yesterday’s sun; the water molecules of today’s river are not identical to those of yesterday’s river; etc.         

The Eleatic Presocratics

So-called because they lived in the Greek colony of Elea in southern Italy, these thinkers attempted to make logical arguments in support of their beliefs. In general, they preferred to argue against the reality of change, motion, and plurality. Given their geographical and philosophical distance from the Milesians, the Eleatics are sometimes characterized as the “western strand” of early Greek thought. 

Parmenides

According to this philosopher, only Being could be said to exist, because non-Being couldn’t even be conceived. That which did not exist could not even be thought about. The world seems to contain change and motion, but reason says that reality is quite different: reality consists of perfect, motionless, featureless, changeless, indivisible Being. If Anaximander’s Boundless could be thought of as a never-ending slushy -- but without the actual slush because it’s not really material -- then Parmenides’ Being would be like a ball of ice of infinite density at absolute zero without actually having any size or shape. Having a size or shape would imply a boundary between something that is and something that is not – but, according to Parmenides, “what is not” could not even be thought.        

Parmenides’ kind of thinking would be categorized as “metaphysical speculation.” He wants to describe the nature of reality as revealed to his “mind’s eye.” He wants to tear away the “veil of illusion” and peer into the true nature of things. The sensible world presents transitory objects that swim into view and then quickly dissipate. Genuine knowledge could only be about objects that do not change, and such objects (or concepts) are revealed to the mind or intellect rather than to the senses. The most promising routes to knowledge would be logic and mathematics because those disciplines deal with objects that are not subject to change.

The ideas of Parmenides would become important for Plato's metaphysics and epistemology. Plato was also interested in epistemic objects that did not change, and he called these unchanging, transcendent, and eternal concepts "Forms." For Plato, the objects of sense experience were just imperfect copies or imitations of these abstract and intelligible concepts.                  

Zeno 

Zeno formulated famous paradoxes concerning motion. The mathematical essence is something like the following: in order to move a distance from point A to point B, an object must first traverse half of that distance. But before this halfway point can be reached, an object must traverse half of that – in other words, a quarter of the distance from A to B; but before reaching a quarter of the distance, an object must cover an eighth of the distance from A to B; etc. It seems that in order for an object to cover even a very short distance, it would need to complete an infinite number of steps. If this were true, then motion would never commence. Modern calculus has pretty much disposed of Zeno’s problem by relying on the concept of a limit. Zeno’s paradox describes what today is called an infinite series, and modern math knows – given certain conditions – how to find their sums.   

Melissus

This minor Eleatic made the argument that Being is infinite, singular and unchanging. Reality consists of just one thing: it seems as if there are many things, but fundamentally there is only one. This sort of ontology is often described as “monistic.” Monism is the doctrine that amidst all of the variety and plurality of the universe, only

one thing exists in an ultimate sense. This ultimate thing has been called by many names in the history of philosophy: the One, God, the Absolute, etc.      

The Pluralist Presocratics

These two thinkers reacted to the lack of plurality and change in Eleatic thought. 

Empedocles of Akragas

Empedocles combined the previous fundamental substances of water, air and fire, added earth to the list, and came up with the traditional “four elements.” Everything in the universe was a mixture and a taking apart of these four. While these elements themselves were unchanging and never-ending, their combinations were responsible for the observed change in the universe. The supreme powers responsible for the cyclical process of combination and recombination were love and strife, who ruled in turns. Love united elements into a sphere (sphairos). The term “love” doesn’t sound very scientific, but if this love were thought of as some kind of attraction – as in electromagnetic attraction between oppositely charged particles – then the theory starts to sound a bit less strange to modern ears.       

Anaxagoras of Klazomenai

Anaxagoras was also a pluralist and he also entertained the idea of mixture, but he did not hold to a cyclical view and he did not limit the number of ingredients to just four. The cosmos started from a state of perfect mixture, but some mysterious entity entered into this chaos and disentangled it. This new entity was called mind (nous), and it was the only thing not mixed with everything else and thus controlled everything else. This mind supervised the whole process of creative separation, but the separation was never absolute: any given piece of stuff always contained some bit of every other kind of stuff. The concept of nous would become important in the cosmologies of Plato and Aristotle: it becomes identified with the demiurge or divine craftsman, who is characterized by Aristotle as "thought thinking itself."       

Democritus of Abdera

A student of Leucippus, Democritus was the most important proponent of what came to be called “atomism,” which was probably the closest any early Greek theory ever came to being in agreement with modern science. Unlike Parmenides, he believed that it was perfectly legitimate to talk about things that were not – vacant spaces where nothing existed, in much the same way a normal person would have no problem talking about a hole in the wall. If it made sense to talk about empty space, then movement would be possible: an object could go from the point at which it was to the point at which it was not. 

What about the objects themselves? As the name of the school suggests, Democritus theorized that the basic elements of reality were things called “atoms,” basic units that

could not be reduced, divided, or reproduced. It’s difficult not to be reminded of the spheres of Empedocles. These atoms were also very similar to Parmenides’ Being, only there were many of them and they could move about. These fundamental units were not visible, but they were ultimately responsible for the “coming into being” of visible things through their interactions. Objects as perceived were sweet or bitter; at the deepest level, only atoms and void existed. Individual atoms were not capable of being sweet, but certain combinations of them could produce the sensation of sweetness.      

The Pythagoreans

Pythagoras of Samos is frequently described as a mysterious figure, one whose life involved strange Orphic rituals and political intrigue. It seems that his religious community in southern Italy was disbanded under less than auspicious circumstances, and his followers fanned out from there. It’s not easy to disentangle what he believed from what his followers believed, so it’s customary to describe their ideas collectively.

It should come as no surprise to anyone who has studied high-school geometry that Pythagorean philosophy gave a special place to mathematical concepts: the keys to understanding the universe were numbers, ratios, and geometric relationships. The Pythagoreans supposedly came to this belief by studying the intervals between musical notes or pitches: for example, the two notes of a perfect octave exhibited a ratio of 2 to 1 with respect to their frequencies; a perfect fifth had a ratio of 3 to 2; and a perfect fourth, 4 to 3. These differences in pitch were described and explained by the geometric configuration of the strings as they vibrated, and did not depend on the material out of which the strings were made.  

The important question about things was not their “fundamental substance,” as the Milesians had thought, but the particular geometric patterns they exhibited. As the British philosopher R.G. Collingwood explains it, the Milesians asked about what an object was made of, whereas Pythagoreans inquired into structure or form. Modern science seems to give some support to the “mystical” Pythagoreans: in chemistry, the properties of a physical substance depend not only on the kinds of atoms present, but also on the geometric configuration of those atoms and on the angles of the bonds between them. A Milesian would have been at a loss to explain the difference between water and ice, since both are made out of the same “stuff,” but a Pythagorean would have just pointed to the difference in molecular configuration.     

The Sophists

In the fifth century there arose a new type of creature: “wise guys” who could twist an argument in order to reach any desired conclusion or either of two contradictory conclusions. To make matters worse, they charged very handsomely for their lectures, where they would teach others their rhetorical and persuasive techniques. So they valued knowledge, but it wasn’t exactly the sort of knowledge that earlier thinkers had pursued. The Sophists were more “practical” and “human-centered.” They didn’t deny the possibility of knowledge, since it would have been awkward to ask for money in exchange for something that didn’t even exist. Their attitude is usually interpreted as a

turning away from the cosmological and metaphysical musings of previous thinkers; they were more concerned with questions of ethics, law and history.

We have a fragment from one such operator named Protagoras: 

“Man is the measure of all things, of things that are that they are, 

and of things that are not that they are not.” 

The Presocratics are usually reduced to a series of parlor-game catchphrases: “All is water”; “All is flux”; “All is One”; “All is number”; etc. If that game is legitimate, then this fragment from Protagoras could be glossed as meaning something like the following: 

“All is … whatever we humans decide that it is.” 

This sort of attitude is usually described as “relativistic”: there are no absolute standards by which to judge good and bad, right and wrong, truth and falsehood, etc. Plato thought Protagoras important enough to immortalize in one of his early “Socratic” dialogues, and it’s safe to say that Plato was concerned about relativism and the kind of "knowledge" imparted by the Sophists.

Glossary of Presocratic Philosophy

Meaning Derived wordsapeiron άπειρον boundless; infinite apeirogonatomos ατομος indivisible atomicdike δικη justice; right; way verdictdoxa δόξα opinion; belief; illusion orthodoxyeidos είδος likeness; class; concept; notion idea; -oidepisteme επιστημη knowledge (logic, math, science, etc.) epistemologyeschaton εσχάτων pertaining to the end (of time) eschatologyistoria ιστορία inquiry; curiosity historykosmos κόσμος world-order cosmologykronos κρόνος father of Zeus; time chronologylogos λόγος word; speech; reason; account logic; -logymigma μίγμα mixture; compound; original chaos magmamoira μοίρα portion; fate; destiny; doom; death mortalitymorphe μορφή shape; form morphologynomos νόμος convention; custom; dispensation; law -nomicsnous νους intelligence; mind noumenononta όντα individual beings ontogeny;

ontology      

ousia ουσία being, in general; essence; full of -ousouranos ουρανός father of Rhea; heavens; sky uranographyphilia φιλία brotherly love; friendship philosophyphusis φύσις nature; primitive matter; primary substance physiologypneuma πνεύμα air; breath; spirit pneumaticpsyche ψυχή breath; soul psychologyrhea ρέα mother of Zeus; flow; flux rheumsophia σοφία wisdom sophistrytechne τέχνη skill; art techniquetheoria θεωρία seeing; curiosity; contemplation theorytropos τρόπος turn; turning tropism

Further Reading

Jonathan Barnes, Early Greek Philosophy (1987; 2001). R.G. Collingwood, The Idea of Nature (1945). F.M. Cornford, From Religion to Philosophy (1912). John Burnet, Early Greek Philosophy (1892).

http://bibliobrevity.blogspot.mx/2012/02/introduction-to-presocratic-philosophy.html