SkepticismSkepticismBy By

Prof. Shadia Abd Prof. Shadia Abd ElkaderElkader

skepticismskepticism

an attitude of doubt or a an attitude of doubt or a disposition to incredulity disposition to incredulity

either in general or toward a either in general or toward a particular objectparticular object, ,

thethe doctrinedoctrine that true that true knowledge or knowledge in a knowledge or knowledge in a particular area is uncertain, particular area is uncertain,

oror the method of suspended the method of suspended judgment, systematic doubt, judgment, systematic doubt,

or criticism that is or criticism that is characteristic of skeptics characteristic of skeptics

((Merriam–WebsterMerriam–Webster). ).

philosophyphilosophy

skepticism refers more specifically skepticism refers more specifically to any one of several propositionsto any one of several propositions. . These include propositions aboutThese include propositions about

the limitations of knowledgethe limitations of knowledge, , a method of obtaining knowledge a method of obtaining knowledge

through systematic doubt and through systematic doubt and continual testingcontinual testing, ,

the arbitrariness, relativity, or the arbitrariness, relativity, or subjectivity of moral valuessubjectivity of moral values, ,

a method of intellectual caution a method of intellectual caution and suspended judgmentand suspended judgment, ,

a lack of confidence in positive a lack of confidence in positive motives for human conduct or motives for human conduct or positive outcomes for human positive outcomes for human enterprises, that isenterprises, that is, , cynicismcynicism andand pessimismpessimism ))Keeton, 1962)Keeton, 1962)

Scientific skepticismScientific skepticism A scientific A scientific ((oror empiricalempirical) ) skeptic is one who skeptic is one who

questions the reliability of certain kinds of questions the reliability of certain kinds of claims by subjecting them to a systematic claims by subjecting them to a systematic investigationinvestigation. . TheThe scientific methodscientific method details the details the specific process by which this investigation ofspecific process by which this investigation of realityreality is conductedis conducted. . Considering the rigor of Considering the rigor of the scientific method, science itself may simply the scientific method, science itself may simply be thought of as an organized form of be thought of as an organized form of skepticismskepticism. . This does not mean that the This does not mean that the scientific skeptic is necessarily a scientist who scientific skeptic is necessarily a scientist who conducts live experiments conducts live experiments ((though this may be though this may be the casethe case)), but that the skeptic generally , but that the skeptic generally accepts claims that are in hisaccepts claims that are in his//her view likely to her view likely to be true based on testablebe true based on testable hypotheseshypotheses andand critical thinkingcritical thinking..

Common topics that scientificallyCommon topics that scientifically--skeptical skeptical literature questions include health claims literature questions include health claims surrounding certain foods, procedures, surrounding certain foods, procedures, and medicines, such asand medicines, such as homeopathyhomeopathy, , ReikiReiki, , Thought Field TherapyThought Field Therapy ( (TFTTFT), ), vertebral vertebral subluxationssubluxations; ; the plausibility ofthe plausibility of supernaturalsupernatural entities entities ((such assuch as ghostsghosts, , poltergeistspoltergeists, , angelsangels, , andand godsgods); ); as well as as well as the existence ofthe existence of ESPESP//telekinesistelekinesis, , psychicpsychic powers, andpowers, and telepathytelepathy ( (and thus the and thus the credibility ofcredibility of parapsychologyparapsychology); );

SkepticismSkepticism

The ward skeptic or sekpticim comes The ward skeptic or sekpticim comes from Greek ward from Greek ward to inquireto inquire..

Sekpticim at its best is not a matter Sekpticim at its best is not a matter of denial , but of inquiring.of denial , but of inquiring.

‘ ‘ How prone to doubt, how How prone to doubt, how cautions are Wise’cautions are Wise’ Homer( Odysse)Homer( Odysse)

SkepticismSkepticism

Beliefs (in a certain area) areBeliefs (in a certain area) are Unjustified Unjustified ((targettarget: internalism): internalism) Unreliable Unreliable ((targettarget: externalism): externalism)

So, (a certain kind of) knowledge is So, (a certain kind of) knowledge is impossibleimpossible

Extreme form: all beliefs are Extreme form: all beliefs are unjustified or unreliable; all unjustified or unreliable; all knowledge is impossibleknowledge is impossible

EmpiricusEmpiricus

There are at least ten modes of skepticism. It can be broken down into three categories: ● Subjective perceiver ● Objective world ● Relation between perceiver and the world.

Subjective PerceiverSubjective Perceiver Both the powers of the senses and of Both the powers of the senses and of

reasoning may vary across personsreasoning may vary across persons. And . And since knowledge is a product of one and/or the since knowledge is a product of one and/or the other, and since neither are reliable, other, and since neither are reliable, knowledge would seem to be in troubleknowledge would seem to be in trouble. . For instance, a For instance, a color-blindcolor-blind person sees the person sees the world quite differently than everyone else. world quite differently than everyone else. Moreover, we cannot even give preference on Moreover, we cannot even give preference on the basis of the power of reason, i.e., by the basis of the power of reason, i.e., by treating the rational animal as a carrier of treating the rational animal as a carrier of greater knowledge than the irrational animal. greater knowledge than the irrational animal. For the irrational animal is still adept at For the irrational animal is still adept at navigating their environment, which navigating their environment, which presupposes the ability to know about some presupposes the ability to know about some aspects of the environment.aspects of the environment.

Secondly, the personality of the Secondly, the personality of the individual might also have an impact individual might also have an impact on what they observe, since (it is on what they observe, since (it is argued) preferences are based on argued) preferences are based on sense-impressions, differences in sense-impressions, differences in preferences can be attributed to preferences can be attributed to differences in the way that people differences in the way that people are affected by the object. are affected by the object.

Third, the perceptions of each individual sense Third, the perceptions of each individual sense seemingly have nothing in common with the seemingly have nothing in common with the other senses: i.e., the color "red" has little to other senses: i.e., the color "red" has little to do with the feeling of touching a red object. do with the feeling of touching a red object. This is manifest when our senses "disagree" This is manifest when our senses "disagree" with each other: for example, a mirage with each other: for example, a mirage presents certain visible features, but is not presents certain visible features, but is not responsive to any other kind of sense. In that responsive to any other kind of sense. In that case, our other senses defeat the impressions case, our other senses defeat the impressions of sight. Given that our senses can be shown to of sight. Given that our senses can be shown to be unreliable by appealing to other senses, and be unreliable by appealing to other senses, and so our senses may be incomplete (relative to so our senses may be incomplete (relative to some more perfect sense that we lack), then it some more perfect sense that we lack), then it follows that all of our senses may be follows that all of our senses may be unreliable. unreliable.

Fourth, our circumstances when we Fourth, our circumstances when we do any perceiving may be either do any perceiving may be either natural or unnatural, i.e., we may be natural or unnatural, i.e., we may be either in a state of wakefulness or either in a state of wakefulness or that of sleep. But it is entirely that of sleep. But it is entirely possible that things in the world possible that things in the world really are exactly as they appear to really are exactly as they appear to be to those in unnatural states (i.e., if be to those in unnatural states (i.e., if everything were an elaborate dream). everything were an elaborate dream).

We have reasons for doubt that are based on We have reasons for doubt that are based on the the relationship between objective "facts" and relationship between objective "facts" and subjective experiencesubjective experience. The positions, distances, . The positions, distances, and places of objects would seem to affect how and places of objects would seem to affect how they are perceived by the person: for instance, they are perceived by the person: for instance, the portico may appear tapered when viewed the portico may appear tapered when viewed from one end, but symmetrical when viewed at from one end, but symmetrical when viewed at the other; and these features are different. the other; and these features are different. Because they are different features, to believe Because they are different features, to believe the object has both properties at the same time the object has both properties at the same time is to believe it has two contradictory properties. is to believe it has two contradictory properties. Since this is absurd, we must suspend judgment Since this is absurd, we must suspend judgment about what properties it possesses about what properties it possesses

We have reasons for doubt that are based on We have reasons for doubt that are based on the the relationship between objective "facts" and relationship between objective "facts" and subjective experiencesubjective experience. The positions, distances, . The positions, distances, and places of objects would seem to affect how and places of objects would seem to affect how they are perceived by the person: for instance, they are perceived by the person: for instance, the portico may appear tapered when viewed the portico may appear tapered when viewed from one end, but symmetrical when viewed at from one end, but symmetrical when viewed at the other; and these features are different. the other; and these features are different. Because they are different features, to believe Because they are different features, to believe the object has both properties at the same time the object has both properties at the same time is to believe it has two contradictory properties. is to believe it has two contradictory properties. Since this is absurd, we must suspend judgment Since this is absurd, we must suspend judgment about what properties it possesses about what properties it possesses

We may also observe that the things we We may also observe that the things we perceive are, in a sense, polluted by perceive are, in a sense, polluted by experience. Any given perception -- say, of experience. Any given perception -- say, of a chair -- will always be perceived within a chair -- will always be perceived within some context or other (i.e., next to a table, some context or other (i.e., next to a table, on a mat, etc.) Since this is the case, we on a mat, etc.) Since this is the case, we can only speak of ideas as they occur in the can only speak of ideas as they occur in the context of the other things that are paired context of the other things that are paired with it. We can never know of the true with it. We can never know of the true nature of the thing, but only how it appears nature of the thing, but only how it appears to us in context to us in context

Along the same lines, the skeptic may insist Along the same lines, the skeptic may insist that all things are relative, by arguing that:that all things are relative, by arguing that:

Absolute appearances either differ from Absolute appearances either differ from relative appearances, or they do not. relative appearances, or they do not.

If absolutes do not differ from relatives, If absolutes do not differ from relatives, then they are themselves relative. then they are themselves relative.

But if absolutes do differ from relatives, But if absolutes do differ from relatives, then they are relative, because all things then they are relative, because all things that differ must differ from something; and that differ must differ from something; and to "differ" from something is to be relative to "differ" from something is to be relative to something. to something.

Finally, we have reason to disbelieve Finally, we have reason to disbelieve that we know anything by looking at that we know anything by looking at problems in understanding problems in understanding the objects the objects themselvesthemselves. Things, when taken . Things, when taken individually, may appear to be very individually, may appear to be very different than when they are in mass different than when they are in mass quantities: for instance, the shavings quantities: for instance, the shavings of a goat's horn are white when taken of a goat's horn are white when taken alone, yet the horn intact is black.alone, yet the horn intact is black.

Skepticism is related to Skepticism is related to epistemologyepistemology, , or the question of whether knowledge or the question of whether knowledge is possible. Skeptics argue that the is possible. Skeptics argue that the belief in something does not belief in something does not necessarily justify an assertion of necessarily justify an assertion of knowledge of it. In this skeptics oppose knowledge of it. In this skeptics oppose foundationalismfoundationalism, which states that , which states that there have to be some basic beliefs there have to be some basic beliefs that are justified without reference to that are justified without reference to others. others.

The skeptical response to this can take The skeptical response to this can take several approaches. First, claiming that several approaches. First, claiming that "basic beliefs" must exist amounts to the "basic beliefs" must exist amounts to the logical fallacy of logical fallacy of argument from ignoranceargument from ignorance combined with the combined with the slippery slopeslippery slope[[citation neededcitation needed]. While a foundationalist ]. While a foundationalist would use would use Munchhausen-TrilemmaMunchhausen-Trilemma as a as a justification for demanding the validity of justification for demanding the validity of basic beliefs, a skeptic would see no problem basic beliefs, a skeptic would see no problem with admitting the result (although the result with admitting the result (although the result is only that there are no is only that there are no certaincertain beliefs). beliefs).

This skeptical approach is rarely taken to its This skeptical approach is rarely taken to its pyrrhonean extreme by most practitioners. pyrrhonean extreme by most practitioners. Several modifications have arisen over the Several modifications have arisen over the years, including the following:years, including the following:

Fictionalism would not claim to have Fictionalism would not claim to have knowledge but will adhere to conclusions on knowledge but will adhere to conclusions on some criterion such as utility, aesthetics, or some criterion such as utility, aesthetics, or other personal criteria without claiming that other personal criteria without claiming that any conclusion is actually "true".any conclusion is actually "true".

Philosophical fideism (as opposed to religious Philosophical fideism (as opposed to religious FideismFideism) would assert the truth of some ) would assert the truth of some proposition, but does so without asserting proposition, but does so without asserting certainty.certainty.

Some forms of Some forms of pragmatismpragmatism would accept utility as a would accept utility as a provisional guide to truth but provisional guide to truth but not necessarily a universal not necessarily a universal decision-maker.decision-maker.

Philosophical fideism (as opposed to Philosophical fideism (as opposed to religious religious FideismFideism) would assert the ) would assert the truth of some proposition, but does so truth of some proposition, but does so without asserting certainty.without asserting certainty.

Some forms of Some forms of pragmatismpragmatism would would accept utility as a provisional guide to accept utility as a provisional guide to truth but not necessarily a universal truth but not necessarily a universal decision-maker.decision-maker.

‘‘By Doubting we come at the TruthBy Doubting we come at the Truth’ ’ ( Cicero).( Cicero). The skeptic ask some deep and challenging The skeptic ask some deep and challenging

questions to which there are no quick and easy questions to which there are no quick and easy answers. As a result of studying these answers. As a result of studying these questions we can come to a deeper questions we can come to a deeper understanding.understanding.

Foe example why we have any of the belief Foe example why we have any of the belief that we hold? How we can the knowledge we that we hold? How we can the knowledge we claim?claim?

These questions shed the light on the These questions shed the light on the foundations for our belief.foundations for our belief.

Division of the beliefDivision of the belief

Past OrientedPast Oriented Present Oriented Present Oriented Future OrientedFuture Oriented

Belief about the Belief about the past/presentpast/present

Past orientedPast oriented I believe that I believe that

Egypt asserted its Egypt asserted its independence in independence in 1952.1952.

I believe that Plato I believe that Plato taught Aristole.taught Aristole.

I believe that I had I believe that I had toast and cheese toast and cheese for breakfastfor breakfast

Present Present orientedoriented

I believe that my I believe that my investment are investment are doing well.doing well.

I believe that my I believe that my son is studying.son is studying.

I believe that it is I believe that it is sunny day outsidesunny day outside..

Future OrientedFuture Oriented

I believe all I believe all Palestine doctorate Palestine doctorate candidate will candidate will answer philosophy answer philosophy questions properly.questions properly.

I believe you well I believe you well eventually eventually understand this understand this course.course.

Sources of Skepticism Sources of Skepticism pastpast

Memory

Testimony

Both

MemoryMemory The skeptic wants to know whether The skeptic wants to know whether

human memory is ever reliable at all. human memory is ever reliable at all. Most of us will admit that memory is not Most of us will admit that memory is not the dependable thing it purports the dependable thing it purports sometimes to be ‘sometimes to be ‘memory is the thing memory is the thing you forget with’ ( Alexander Chase).you forget with’ ( Alexander Chase).

How do we know that our memory is reliable? How do we know that our memory is reliable? At least I know that my memory is often At least I know that my memory is often reliable. How do I know? Simple I can recall reliable. How do I know? Simple I can recall many times in the past when I seem to many times in the past when I seem to remember parking in a particular place and remember parking in a particular place and there the car in fact was.there the car in fact was.

Justify Memory →reasoning which Justify Memory →reasoning which assumes the truth of the thing → assumes the truth of the thing → produce evidenceproduce evidence

TestimonyTestimonyTestimony is our main source of belief Testimony is our main source of belief

about the past. How do I know that what about the past. How do I know that what other people tell me is ever the truth?.... other people tell me is ever the truth?.... In response to the skeptics what other In response to the skeptics what other people have told me has turned out to be people have told me has turned out to be true, therefore testimony is sometimes true, therefore testimony is sometimes reliable.reliable.

Sources of Present Sources of Present OrientedOrientedBeliefsBeliefs

MemoryMemory TestimonyTestimony ExperienceExperience

Sense ExperienceSense Experience

A great number of present moment A great number of present moment beliefs are just rooted in the beliefs are just rooted in the immediacy and intimacy of a sense immediacy and intimacy of a sense experience.experience.

Sources of SkepticisimSources of Skepticisim

Present/Future oriented

Memory Testimony Sense of experience

Radical SkepticismRadical Skepticism

It suggests a hypothesis so opposed to It suggests a hypothesis so opposed to what we ordinary assume that if it were what we ordinary assume that if it were true, an true, an enormous number of beliefs enormous number of beliefs that we knowthat we know would be falsewould be false. The . The radical skeptic points out that radical skeptic points out that continuing to hold our normal belief continuing to hold our normal belief requires denying this hypothesis or requires denying this hypothesis or believing it to be false. believing it to be false. Then the typical Then the typical question will be how we know that it is question will be how we know that it is false.false.

Radical sketicism about Radical sketicism about the pastthe past

The 5 minute hypothesisThe 5 minute hypothesis This hypothesis is incompatible with all This hypothesis is incompatible with all

my beliefs concerning anything 5 my beliefs concerning anything 5 minutes or more in the past.’ minutes or more in the past.’ The entire The entire universe sprang into existence from universe sprang into existence from nothing 5 minutes ago, exactly as nothing 5 minutes ago, exactly as then it was, apparent wrinkles on then it was, apparent wrinkles on peoples’ faces and other signs of age peoples’ faces and other signs of age all instantly formed and thoroughly all instantly formed and thoroughly deceptive’.deceptive’.

The skeptic does not believe the five The skeptic does not believe the five minute hypothesis to be true and he is not minute hypothesis to be true and he is not to get us to believe it. He is just pointing to get us to believe it. He is just pointing out that the belief we now have commit us out that the belief we now have commit us to being convinced that it is false, and he to being convinced that it is false, and he wants to ask us how in the world we know wants to ask us how in the world we know it, or even reasonably believe it to be it, or even reasonably believe it to be false. It would just mean that we should false. It would just mean that we should withhold our judgment on it, and become withhold our judgment on it, and become correspondingly uncertain about correspondingly uncertain about everything in the past over 5 minutes ago.everything in the past over 5 minutes ago.

Radical Skepticism about Radical Skepticism about the presentthe present

Descartes used a certain method to try to isolate a definite truth, or something that can not be doubted. Descartes tried to achieve this absolute truth by starting analysis with radical doubt.

Method of doubtMethod of doubt He used 3 different foundations of belief

in this method: Analysis of the Senses

The Dream Hypothesis

The Evil Genius

Analysis of the Senses?Analysis of the Senses?

Descartes doubts that he can trust his Descartes doubts that he can trust his senses because they are occasionally senses because they are occasionally wrong. An example of this is a short-wrong. An example of this is a short-haired woman may look like a man haired woman may look like a man from far away.from far away.

Analysis of the Senses

SkepticaSkeptical l

HypotheHypothesissis

What What Can Be Can Be

DoubtedDoubted

What What Cannot Cannot

be be doubteddoubted

FacultFacultyy

ScieSciencence

The The Senses Senses Deceive Deceive us at a us at a distancedistance

The size The size of the sun of the sun and stars, and stars, the shape the shape of towers of towers and the and the color of color of mountainsmountains

Things Things observed observed close at close at hand, e.g. hand, e.g. that I am that I am now now seated in a seated in a room etc.room etc.

The The sensessenses

AstroAstronomnomyy

”What has deceived me once may deceive me again.”--Descartes

The Dream HypothesisThe Dream Hypothesis

Descartes believes that there are no sure Descartes believes that there are no sure signs for him to tell whether he is awake or signs for him to tell whether he is awake or asleep. Since he cannot trust his senses, he asleep. Since he cannot trust his senses, he concludes that there is no way to determine concludes that there is no way to determine whether he is dreaming or awake. whether he is dreaming or awake.

Although he does say that there are Although he does say that there are certain “truths” that are consistent, certain “truths” that are consistent, whether he is awake or asleep. whether he is awake or asleep. Example: two plus three equals five, Example: two plus three equals five, and that a square has four sides in and that a square has four sides in his sleep, and while awake.his sleep, and while awake.

The Dream HypothesisThe Dream Hypothesis

SkepticaSkeptical l

HypotheHypothesissis

What Can What Can Be Be

DoubtedDoubted

What What Cannot Cannot

be be doubteddoubted

FacultFacultyy

ScienSciencece

The Dream The Dream HypothesisHypothesis

That I am That I am seated in this seated in this room, that I am room, that I am clothed, that I clothed, that I have hands, have hands, eyes or a body eyes or a body at allat all

Truths of Truths of mathematimathematics, eg. 2+2 cs, eg. 2+2 = 4, = 4, squares squares have four have four sides etc.sides etc.

The The imaginatimaginationion

PhysiolPhysiology, ogy, physics, physics, medicinmedicine etce etc

What I perceive by the senses may be the deceptions of a dream.”--Descartes

The Evil Genius?The Evil Genius?

Descartes' most powerful skeptical Descartes' most powerful skeptical hypothesis was that there was an evil hypothesis was that there was an evil genius trying to deceive him. This genius trying to deceive him. This would challenge the belief that the would challenge the belief that the physical world exists, the belief in physical world exists, the belief in simple statements of fact, and it would simple statements of fact, and it would then question the validity of reason then question the validity of reason itself. But not even an evil genius could itself. But not even an evil genius could lead us to believe that we ourselves lead us to believe that we ourselves don’t exist.don’t exist.

Radical Skepticism about Radical Skepticism about the futurethe future

The futuristic points out that the future The futuristic points out that the future does not exist. In order for a belief to does not exist. In order for a belief to be true, the object about which it is be true, the object about which it is true must be among the furniture of true must be among the furniture of reality, and that object must have the reality, and that object must have the property attributed to it in that belief. property attributed to it in that belief. For it to be true that grass is green, For it to be true that grass is green, there must be such a thing as grass, there must be such a thing as grass, and it must have the property of being and it must have the property of being green.green.

Since he is able to think, then it is derived that he is alive and breathing.

Meaning that each idea that develops in our brain cannot be doubted because we think, it´s not mistaken.

Rests upon the principle of sufficient reason

Meaning that to create a big effect a bigger cause is needed ‘It is impossible to derive the more perfect from the less perfect.’

Once perfection is pointed out to someone, then he cannot deny having the idea. Since the idea is already there, therefor it is natural. When everyone believes an idea is perfect, nothing can prove it wrong.

Thesis and Thesis and RecommendationRecommendation

Thesis: Knowledge (of a certain kind) is Thesis: Knowledge (of a certain kind) is impossibleimpossible

Recommendation: So, one ought to Recommendation: So, one ought to inquireinquire..

Problem: How can the extreme skeptic get Problem: How can the extreme skeptic get from the thesis to the recommendation?from the thesis to the recommendation?

It seems that it requires an inferenceIt seems that it requires an inference Extreme skepticism undercuts such Extreme skepticism undercuts such

inferencesinferences

Daoism: Zhuangzi (c. -Daoism: Zhuangzi (c. -350)350)

Intellectual distinctions correspond to nothing in Intellectual distinctions correspond to nothing in realityreality

There’s no point to doing anythingThere’s no point to doing anything Zhu Xi: “Laozi still wanted to do something, but Zhu Xi: “Laozi still wanted to do something, but

Zhuangzi didn’t want to do anything at all.”Zhuangzi didn’t want to do anything at all.”

Identity of ContrariesIdentity of Contraries

Can we be completely objective?Can we be completely objective? No— the objective and subjective are No— the objective and subjective are

intertwinedintertwined Objective —> subjective: you can Objective —> subjective: you can

reach objective knowledge only by reach objective knowledge only by depending on your own subjective depending on your own subjective mental statesmental states

Subjective —> objective: your being Subjective —> objective: your being in a mental state depends on and in a mental state depends on and gives rise to objective facts about yougives rise to objective facts about you

Three in the MorningThree in the Morning ““A keeper of monkeys said with regard to A keeper of monkeys said with regard to

their rations of chestnuts that each monkey their rations of chestnuts that each monkey was to have three in the morning and four at was to have three in the morning and four at night. But at this the monkeys were very night. But at this the monkeys were very angry, so the keeper said they might have angry, so the keeper said they might have four in the morning and three at night, with four in the morning and three at night, with which arrangement they were all well which arrangement they were all well pleased. The actual number of the chestnuts pleased. The actual number of the chestnuts remained the same, but there was an remained the same, but there was an adaptation to the likes and dislikes of those adaptation to the likes and dislikes of those concerned. Such is the principle of putting concerned. Such is the principle of putting oneself into subjective relation with oneself into subjective relation with externals.”externals.”

Skepticism v. RelativismSkepticism v. Relativism

Relativism: There are no universally valid Relativism: There are no universally valid truths about the worldtruths about the world

Beliefs are true only relative to aBeliefs are true only relative to a society culture historical epoch interpretative community individual person

Skepticism v. RelativismSkepticism v. Relativism

Knowledge of truth is impossible, Knowledge of truth is impossible, because…because… Skepticism: our beliefs are unjustified or Skepticism: our beliefs are unjustified or

unreliableunreliable Relativism: there is no truth to knowRelativism: there is no truth to know

Protagoras: “Man is the measure of all Protagoras: “Man is the measure of all things. . . .”things. . . .”

Skepticism v. RelativismSkepticism v. Relativism

These might be seen as allies:These might be seen as allies: If we can’t know truth, why think there’s If we can’t know truth, why think there’s

any truth to know?any truth to know? Or as enemies:Or as enemies:

Skeptics stress the distance between Skeptics stress the distance between appearance and realityappearance and reality

Relativists tend to bring them closerRelativists tend to bring them closer

Identity of All ThingsIdentity of All Things

We draw distinctionsWe draw distinctions But things aren’t distinct in But things aren’t distinct in

the worldthe world Everything is Everything is DaoDao Everything is in the eye of Everything is in the eye of

the beholderthe beholder There is no objectivityThere is no objectivity There is no knowledgeThere is no knowledge

VariabilityVariability

VariabilityVariability: Things are perceived : Things are perceived differently by different beings at different differently by different beings at different timestimes

UndecidabilityUndecidability: There is no neutral way to : There is no neutral way to determine which perceptions are determine which perceptions are trustworthytrustworthy

Sceptical thesisSceptical thesis: Therefore, knowledge is : Therefore, knowledge is impossibleimpossible

Problem of the CriterionProblem of the Criterion

UndecidabilityUndecidability: There is no neutral way : There is no neutral way to tell which perceptions ought to be to tell which perceptions ought to be trustedtrusted

We need a criterion for determining We need a criterion for determining thisthis

But where could we get it? Even if we But where could we get it? Even if we could get one, we couldn’t justify itcould get one, we couldn’t justify it

Possibility of DreamingPossibility of Dreaming ““Those who dream of the Those who dream of the

banquet, wake to banquet, wake to lamentation and sorrow. lamentation and sorrow. Those who dream of Those who dream of lamentation and sorrow lamentation and sorrow wake to join the hunt. wake to join the hunt. While they dream, they do While they dream, they do not know that they dream. not know that they dream. Some will even interpret Some will even interpret the very dream they are the very dream they are dreaming: and only when dreaming: and only when they awake do they know it they awake do they know it was a dream.”was a dream.”

Possibility of DreamingPossibility of Dreaming ““Once upon a time, I, Zhuangzi, dreamt Once upon a time, I, Zhuangzi, dreamt

I was a butterfly, fluttering hither and I was a butterfly, fluttering hither and thither, to all intents and purposes a thither, to all intents and purposes a butterfly. I was conscious only of butterfly. I was conscious only of following my fancies as a butterfly, and following my fancies as a butterfly, and was unconscious of my individuality as a was unconscious of my individuality as a man. Suddenly, I awaked, and there I man. Suddenly, I awaked, and there I lay, myself again. Now I do not know lay, myself again. Now I do not know whether I was then a man dreaming I whether I was then a man dreaming I was a butterfly, or whether I am now a was a butterfly, or whether I am now a butterfly, dreaming I am a man.”butterfly, dreaming I am a man.”

Zhuangzi’s Zhuangzi’s RecommendationRecommendation

““The true sage rejects all distinctions The true sage rejects all distinctions of this and that. He takes his refuge of this and that. He takes his refuge in in DaoDao and places himself in and places himself in subjective relation with all things.”subjective relation with all things.”

But how can he justify his But how can he justify his recommendation?recommendation?

Does it follow from his thesis?Does it follow from his thesis? Does he know it?Does he know it?

Philo of Alexandria (-20 - Philo of Alexandria (-20 - 40)40)

First to attempt project of First to attempt project of reconciling Jewish reconciling Jewish scriptures with Greek scriptures with Greek philosophyphilosophy

Tries to construct sceptical Tries to construct sceptical arguments without arguments without metaphysical metaphysical presuppositions in “On presuppositions in “On Drunkenness”Drunkenness”

VariabilityVariability

Variation in perception Variation in perception among different species, among different species, different people, even different people, even same person on different same person on different occasionsoccasions

How do we know which How do we know which portray reality portray reality accurately?accurately?

Argument from IllusionArgument from Illusion

We often misperceive We often misperceive thingsthings

There is no way to tell There is no way to tell when we’re when we’re misperceiving thingsmisperceiving things

So, on any given So, on any given occasion, we might be occasion, we might be misperceiving thingsmisperceiving things

ComparisonComparison

We know, not things in We know, not things in themselves, but things in themselves, but things in relation to other things— relation to other things— including usincluding us

We know things only as We know things only as they relate to usthey relate to us

We can’t distinguish We can’t distinguish what’s really in the object what’s really in the object from what we are from what we are contributingcontributing

Zeno’s ParadoxesZeno’s Paradoxes

Arguments against Arguments against possibility of motionpossibility of motion

Runner: one must Runner: one must first go halfway. . . .first go halfway. . . .

Achilles and the Achilles and the Tortoise: The Tortoise: The tortoise gets a head tortoise gets a head start; Achilles must start; Achilles must first get to its first get to its starting point, but by starting point, but by then it has moved onthen it has moved on

Sextus Empiricus (c. Sextus Empiricus (c. 200)200)

We can’t tell what’s in We can’t tell what’s in the object and what we the object and what we contributecontribute

Knowledge of “external Knowledge of “external underlying objects” is underlying objects” is impossibleimpossible

Recommendation: Recommendation: suspend judgmentsuspend judgment

Problem of the Criterion, Problem of the Criterion, 22

Is there a criterion Is there a criterion of truth?of truth?

To settle this, we To settle this, we need a criterionneed a criterion

But that’s what’s But that’s what’s at issue!at issue!

Dogmatist must Dogmatist must argue in a circle,argue in a circle,

Or face infinite Or face infinite regressregress

Suspension & Suspension & AtaraxiaAtaraxia

Suspension of Suspension of judgment —> peace judgment —> peace of mind (of mind (ataraxiaataraxia))

But the sceptic But the sceptic can’t know this, or can’t know this, or even assert iteven assert it

It just happensIt just happens

Peace of MindPeace of Mind

““The Skeptic, in fact, had the same The Skeptic, in fact, had the same experience which is said to have befallen experience which is said to have befallen the painter Apelles. Once, they say, when the painter Apelles. Once, they say, when he was painting a horse and wished to he was painting a horse and wished to represent in the painting the horses foam, represent in the painting the horses foam, he was so unsuccessful that he gave up the he was so unsuccessful that he gave up the attempt and flung at the picture the sponge attempt and flung at the picture the sponge on which he used to wipe the paints off his on which he used to wipe the paints off his brush, and the mar of the sponge produced brush, and the mar of the sponge produced the effect of a horse’s foam.”the effect of a horse’s foam.”

Peace of MindPeace of Mind

““So, too, the Skeptics were So, too, the Skeptics were in hopes of gaining quietude in hopes of gaining quietude by means of a decision by means of a decision regarding the disparity of regarding the disparity of the objects of sense and of the objects of sense and of thought, and being unable to thought, and being unable to effect this they suspended effect this they suspended judgment; and they found judgment; and they found that quietude, as if by that quietude, as if by chance, followed upon their chance, followed upon their suspense, even as a shadow suspense, even as a shadow follows its substance.”follows its substance.”

Nagarjuna (c. 1000)Nagarjuna (c. 1000)

Mahayana Buddhist, 14th Mahayana Buddhist, 14th Indian Zen patriarchIndian Zen patriarch

Founder of Madhyamika Founder of Madhyamika BuddhismBuddhism

Destroy theorizingDestroy theorizing Leave ordinary life alone: Leave ordinary life alone:

“For we do not speak “For we do not speak without accepting, for without accepting, for practical purposes, the practical purposes, the work-a-day world”work-a-day world”

Attack on Attack on pramanaspramanas

I know something I know something because it arises from because it arises from a reliable source of a reliable source of knowledgeknowledge

But how do I know But how do I know that source of that source of knowledge is reliable?knowledge is reliable?

Need a Need a pramanapramana of of pramanaspramanas, etc.— , etc.— infinite regressinfinite regress

Nagarjuna’s Regress Nagarjuna’s Regress ArgumentArgument

““And if, for you, there is a source [of And if, for you, there is a source [of knowledge] of each and every object of knowledge] of each and every object of proof,proof,Then tell how, in turn, for you there is Then tell how, in turn, for you there is proof of those sources.proof of those sources.If by other sources [of knowledge] there If by other sources [of knowledge] there would be the proof of a source-- that would be the proof of a source-- that would be an ‘infinite regress’;would be an ‘infinite regress’;in that case neither a beginning, middle, in that case neither a beginning, middle, or and end is proved.”or and end is proved.”

PramanaPramana of of pramanaspramanas

Sources of knowledge: Sources of knowledge: perception, analogy, perception, analogy, testimony, inferencetestimony, inference

Knowledge is justified Knowledge is justified only if we know we’re only if we know we’re using the appropriate using the appropriate sourcesource

What could be source What could be source of knowledge for that?of knowledge for that?

QuietismQuietism

If knowledge is impossible, If knowledge is impossible, how can we know the truth of how can we know the truth of skepticism?skepticism?

Isn’t skepticism unreliable or Isn’t skepticism unreliable or unjustified?unjustified?

““If I would make any If I would make any proposition whatever, then by proposition whatever, then by that I would have a logical that I would have a logical error; But I do not make a error; But I do not make a proposition, therefore I am not proposition, therefore I am not in error.”in error.”

NyayaNyaya Response Response We don’t need a We don’t need a pramanapramana

for for pramanaspramanas Means of knowledge Means of knowledge

((pramanaspramanas) and objects of ) and objects of knowledge (knowledge (prameyasprameyas) ) support each othersupport each other

Sutra 16:Sutra 16: Just as the Just as the 'measuring instrument' 'measuring instrument' (which usually has the (which usually has the status of a status of a pramanapramana) can be ) can be a a prameyaprameya as well (i.e. as well (i.e. when its own accuracy is when its own accuracy is subject to investigation).subject to investigation).

ScalesScales

Analogy: scalesAnalogy: scales How do we test the How do we test the

reliability of a scale?reliability of a scale? We compare We compare

weights it gives for weights it gives for objects with known objects with known weights by other weights by other scalesscales

We don’t need a We don’t need a “scale of scales”“scale of scales”

NyayaNyaya Coherentism Coherentism

No foundation, no No foundation, no givengiven

One thing may be One thing may be justifier or justified, justifier or justified, depending on depending on circumstancescircumstances

Epistemic role Epistemic role depends on contextdepends on context

LuminosityLuminosity

Sutra 19Sutra 19: . . . these : . . . these (i.e. perception (i.e. perception etc.) are etc.) are apprehended in apprehended in the same way as the same way as the light of a lamp.the light of a lamp.

Light can be both Light can be both means of seeing means of seeing and the thing seenand the thing seen

Gangesa (c. 1350)Gangesa (c. 1350) Local doubt (e.g., Local doubt (e.g.,

eyes, scale): we doubt eyes, scale): we doubt when something when something anomalous happens, anomalous happens, and resolve as in the and resolve as in the NyayaNyaya--sutrasutra

Global doubt: we have Global doubt: we have no reason to entertain; no reason to entertain; makes no sense to say makes no sense to say everything is anomalyeverything is anomaly

Pragmatic InconsistencyPragmatic Inconsistency ““Thus it has been said (by Thus it has been said (by

Udayana): "That is doubted Udayana): "That is doubted concerning which as doubted there concerning which as doubted there occurs no contradiction with the occurs no contradiction with the doubter's action." For it is not doubter's action." For it is not possible at once to resort regularly possible at once to resort regularly to fire and the like for smoke and to fire and the like for smoke and the like and to doubt that fire the like and to doubt that fire causes it (it would be meaningless causes it (it would be meaningless behavior). This is how we should behavior). This is how we should understand Udayana's saying. . . . understand Udayana's saying. . . . It is the doubter's own behavior It is the doubter's own behavior that proves the lie to the doubt, that proves the lie to the doubt, i.e., that blocks it.”i.e., that blocks it.”

Augustine (354-430)Augustine (354-430)

Logical and mathematical Logical and mathematical truths can be known, even if truths can be known, even if sceptical arguments succeedsceptical arguments succeed

““I am certain that either I am certain that either there is only one world or there is only one world or there are more worlds than there are more worlds than one. I am likewise certain one. I am likewise certain that if there are more worlds that if there are more worlds than one, their number is than one, their number is either finite or infinite.”either finite or infinite.”

Augustine: PerceptionAugustine: Perception ““In fact, I believe that the In fact, I believe that the

senses are not senses are not untrustworthy either untrustworthy either because deranged persons because deranged persons suffer illusions, or because suffer illusions, or because we see things wrongly we see things wrongly when we are asleep. If the when we are asleep. If the senses correctly intimate senses correctly intimate things to the vigilant and things to the vigilant and the sane, it is no affair of the sane, it is no affair of theirs what the mind of a theirs what the mind of a sleeping or insane person sleeping or insane person may fancy for itself.”may fancy for itself.”

Augustine: AppearancesAugustine: Appearances ““Restrict your assent to the mere Restrict your assent to the mere

fact of your being convinced that fact of your being convinced that it appears thus to you. Then it appears thus to you. Then there is no deception, for I do not there is no deception, for I do not see how even an Academic see how even an Academic [Skeptic] can refute a man who [Skeptic] can refute a man who says: ‘I know that this appears says: ‘I know that this appears white to me. I know that I am white to me. I know that I am delighted by what I am hearing. I delighted by what I am hearing. I know that this smells pleasant to know that this smells pleasant to me. I know that this tastes sweet me. I know that this tastes sweet to me. I know that this feels cold to me. I know that this feels cold to me.’”to me.’”

Self-knowledgeSelf-knowledge ““I am most certain that I am, I am most certain that I am,

and that I know and delight in and that I know and delight in this. In respect of these truths, I this. In respect of these truths, I am not at all afraid of the am not at all afraid of the arguments of the Academicians, arguments of the Academicians, who say, What if you are who say, What if you are deceived? For if I am deceived, I deceived? For if I am deceived, I am. . . . [Certainly I am not am. . . . [Certainly I am not deceived in this knowledge that deceived in this knowledge that I am. And, consequently, neither I am. And, consequently, neither am I deceived in knowing that I am I deceived in knowing that I know. For, as I know that I am, know. For, as I know that I am, so I know this also, that I so I know this also, that I know.”know.”