Humanities 3V. The Scientific Revolution

Lecture 22

A Mechanical World

Outline

• The Doctrine of Mechanism

• Hobbes and the New Science

• Hobbes’ Life

• The Big Picture: Religion and Politics

Science and the Unification ofNature

• No distinction between the celestial and theterrestrial

• No distinction between “natural” and “unnatural”(or “violent”) motion

• All causation is efficient causation• All inanimate objects are just matter; no

hylomorphic (form-matter) substances• Explanation of life remains an outstanding

problem in 17th c.

Doctrine of Mechanism• All natural phenomena can be explained in terms

of changes in the sizes, shapes and motions ofparts of matter

• All change is explained in terms of efficientcausation, i.e. bodies acting directly on bodies incollision.

• Nature as a “clockwork”• Later in the 17th c. century the sufficiency of this

view is challenged and the need for anindependent property of force is recognized(Leibniz, Newton). Kinematics (theory ofmotion) is replaced by dynamics.

Applications of the Doctrine• In the Assayer, Galileo argues that there is a

fundamental difference between the “primary andreal attributes” of matter (size, shape, motion, andsolidity) and those properties we perceive bodiesto have on the basis of our senses.

• “from the point of view of the subject in whichthey seem to inhere, these tastes, odors, colors,etc., are nothing but empty names; rather theyinhere only in the sensitive body, such that if oneremoves the animal, then all these qualities aretaken away and annihilated.” (p. 185)

• This is a fundamental challenge toAristotle’s theory of sense perception andrepresents a first attempt to apply thedoctrine of mechanism to human beings(see Leviathan, ch. 1).

• By itself, it leaves unsettled the question ofsensory qualities: if they are not realproperties of bodies, what are they? Ideasin a non-material mind (Descartes)?

• More generally, to what extent can thephenomena of human life be explainedmechanistically?

Moving forward and backward• Galileo takes no stand on such questions. He is

content to affirm the orthodox Catholic view ofhuman beings as made in God’s image.

• Rene Descartes (1596-1650) makes a morethorough investigation of these questions andconcludes that human beings, unlike animals,consist of a body united to an immaterialconscious, rational mind (dualism).

• Other thinkers at this time look back to the ancientphilosopher, Epicurus (4th c. BCE), who held thatthe universe consists solely of matter in motion(materialism).

Descartes’ Dualism• Mechanism: All physical phenomena can be

explained in terms of changes in the size, shapeand motion of matter. These occur in accordancewith laws of nature established by God.

• Knowledge: The most reliable source ofknowledge is not sensory experience but reason.Our most certain knowledge is of the existenceand nature of our own mind. (Cogito ergo sum =I think, therefore I am)

• Dualism: All substances are either matter orrational minds. The principal attribute of matter isspatial extension. The principal attribute of mindis conscious thought.

The Uniqueness of HumanBeings

• Human beings are “made in God’s image”and are the divinely ordained “masters” ofnature

• We alone have non-material, conscious,rational minds

• We alone have “freedom of will” on thebasis of which we can choose rightly orwrongly, and are held responsible for ouractions.

Epicurus’ Universe• The cosmos consists solely of moving particles of

matter (atoms) and empty space.• When atoms collide they form larger complex

structures, including animals, human bodies, and“worlds” (solar systems)

• Some of these structures survive, some don’t. Itall depends on how they interact with the rest ofnature.

• The cosmos exists eternally. The gods, if theyexist, care nothing for the concerns of humanbeings.

Epicurus’ Ethics• The only thing good in itself is pleasure; the only

thing bad, pain• The end, or goal, of human life (=happiness) is a

life in which physical pain and psychologicaldisturbance are minimized.

• The latter is achieved by eliminating fear of deathand fear of the gods, and limiting our desires tothose that are natural and necessary.

• Virtue is valuable only as a means to this end.• Justice and injustice are merely conventional, as

determined by the laws of a state.

Thomas Hobbes• The philosopher who most clearly advanced these

views in the 17th c. was Hobbes, who is mostfamous for his book Leviathan (1651).

• In it he argues against the view, common to mostancient Greek philosophy and Christianity, thatpolitical life is natural to human beings.

• Hobbes held that the natural condition of humanbeings is one of conflict and even war.

• He reaches this conclusion by starting from aphilosophical position similar to Epicurus’.

Hobbes is a…• Materialist: the only real things are bodies in

motion.• Empiricist: all knowledge originates in sense

perception, and has as its object particular bodiesand their properties.

• Nominalist: speech can be meaningfully used onlyto refer to bodies and their properties and to expressthe desires and aversions of human beings.

• Reason “is nothing but reckoning (that is, addingand subtracting) of the consequences of generalnames agreed upon for the marking and signifyingof our thoughts.”

Hobbes: A Very Long Life• 1588 Hobbes born• 1599 Shakespeare, Julius Caesar• 1603 Death of Elizabeth I, coronation of

James I; Hobbes enters Oxford• 1605 Gunpowder Plot

Bacon, Advancement of Learning• 1611 Publication of King James Bible• 1616 Death of Shakespeare• 1620 Bacon, New Organon• 1620s Hobbes serves as Bacon’s secretary

Hobbes and the English Civil War• 1642 English Civil War begins (central issue:

the balance of power between king andparliament, especially in the levying of taxes); Hobbes publishes his first political treatise (De Cive) in Paris.

• 1649 Execution of Charles I; Commonwealthinstituted under Oliver Cromwell.

• 1651 Leviathan published; Hobbes returns toEngland.

• 1660 Restoration of Charles II.

• 1661-2 Hobbes’ debate with Boyle over the vacuum and the pressure of air

• 1665 Founding of the Royal Society• 1667 Milton, Paradise Lost• 1676 Hobbes publishes verse

translations of Iliad and Odyssey• 1679 Hobbes’ death (aged 91)• 1683 Oxford condemns and burns De Cive

and Leviathan• 1687 Publication of Newton’s Principia

The Big Picture:Religion and Politics

• By the end of the 16th century, the monolithicauthority of the Roman Catholic church hasbroken down; Europe faces irresolvabledisagreement over religion, and endless war(fought on religious and political grounds).

• Thinkers such as Montaigne urge the virtue oftoleration (Catholics and Lutherans in Germany;Jews in Amsterdam).

• Missing is a philosophical framework in whichindividual liberty (esp. freedom of conscience) canbe upheld within a stable political order.

• Two stumbling blocks:• the relation of religion and science• the relation of religion and politics

• Galileo claims to have a solution to the firstproblem but has nothing to say about thesecond.

• Hobbes goes further in challenging traditionaltheological assumptions about human beings,and claiming that a stable political solution canbe found, based on a revised scientificunderstanding of human beings.

Hobbes’ Ethical Theory• Given Hobbes’ starting points (materialism,

empiricism, nominalism), he is led to a radicallynew understanding of ethics as “the science ofpassions.” (ch. 6; see ch. 4 [24])

• Passions are just motions of matter: the “smallbeginnings of motion within the body of man,before they appear in walking, speaking, striking,and other visible actions.”

• Passions are of two basic types: the endeavortoward something is “appetite” or “desire”; theendeavor away from something is “aversion.” Theother passions are defined in terms of these.

The Relativity of Good and Evil“But whatsoever is the object of any man’s appetite or desirethat is it which he for his part calleth good; and the object ofhis hate and aversion, evil; and of his contempt, vile andinconsiderable. For these words of good, evil, andcontemptible are ever used with relation to the person thatuses them, there being nothing simply and absolutely so, norany common rule of good and evil to be taken from thenature of the objects themselves, but from the person of theman, where there is no commonwealth, or, in acommonwealth, from the person that representeth it, or froman arbitrator or judge whom men disagreeing shall byconsent set up and make his sentence the rule thereof.”