Humanities 3 V. 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 of Nature No distinction between the celestial and the terrestrial 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 of parts of matter All change is explained in terms of efficient causation, i.e. bodies acting directly on bodies in collision. Nature as a clockwork Later in the 17th c. century the sufficiency of this view is challenged and the need for an independent property of force is recognized (Leibniz, Newton). Kinematics (theory of motion) is replaced by dynamics.
Applications of the Doctrine In the Assayer, Galileo argues that there is a fundamental difference between the primary and real attributes of matter (size, shape, motion, and solidity) and those properties we perceive bodies to have on the basis of our senses. from the point of view of the subject in which they seem to inhere, these tastes, odors, colors, etc., are nothing but empty names; rather they inhere only in the sensitive body, such that if one removes the animal, then all these qualities are taken away and annihilated. (p. 185)
This is a fundamental challenge to Aristotle s theory of sense perception and represents a first attempt to apply the doctrine of mechanism to human beings (see Leviathan, ch. 1). By itself, it leaves unsettled the question of sensory qualities: if they are not real properties of bodies, what are they? Ideas in a non-material mind (Descartes)? More generally, to what extent can the phenomena of human life be explained mechanistically?
Moving forward and backward Galileo takes no stand on such questions. He is content to affirm the orthodox Catholic view of human beings as made in God s image. Rene Descartes (1596-1650) makes a more thorough investigation of these questions and concludes that human beings, unlike animals, consist of a body united to an immaterial conscious, rational mind (dualism). Other thinkers at this time look back to the ancient philosopher, Epicurus (4th c. BCE), who held that the universe consists solely of matter in motion (materialism).
Descartes Dualism Mechanism: All physical phenomena can be explained in terms of changes in the size, shape and motion of matter. These occur in accordance with laws of nature established by God. Knowledge: The most reliable source of knowledge is not sensory experience but reason. Our most certain knowledge is of the existence and nature of our own mind. (Cogito ergo sum = I think, therefore I am) Dualism: All substances are either matter or rational minds. The principal attribute of matter is spatial extension. The principal attribute of mind is conscious thought.
The Uniqueness of Human Beings Human beings are made in God s image and are the divinely ordained masters of nature We alone have non-material, conscious, rational minds We alone have freedom of will on the basis of which we can choose rightly or wrongly, and are held responsible for our actions.
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. It all depends on how they interact with the rest of nature. The cosmos exists eternally. The gods, if they exist, care nothing for the concerns of human beings.
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 psychological disturbance are minimized. The latter is achieved by eliminating fear of death and fear of the gods, and limiting our desires to those 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 most famous for his book Leviathan (1651). In it he argues against the view, common to most ancient Greek philosophy and Christianity, that political life is natural to human beings. Hobbes held that the natural condition of human beings is one of conflict and even war. He reaches this conclusion by starting from a philosophical 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 bodies and their properties. Nominalist: speech can be meaningfully used only to refer to bodies and their properties and to express the desires and aversions of human beings. Reason is nothing but reckoning (that is, adding and subtracting) of the consequences of general names agreed upon for the marking and signifying of 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 1649 1651 1660 English Civil War begins (central issue: the balance of power between king and parliament, especially in the levying of taxes); Hobbes publishes his first political treatise (De Cive) in Paris. Execution of Charles I; Commonwealth instituted under Oliver Cromwell. Leviathan published; Hobbes returns to England. Restoration of Charles II.
1661-2 1665 1667 1676 Hobbes debate with Boyle over the vacuum and the pressure of air Founding of the Royal Society Milton, Paradise Lost Hobbes publishes verse translations of Iliad and Odyssey 1679 Hobbes death (aged 91) 1683 1687 Oxford condemns and burns De Cive and Leviathan Publication of Newton s Principia
The Big Picture: Religion and Politics By the end of the 16th century, the monolithic authority of the Roman Catholic church has broken down; Europe faces irresolvable disagreement over religion, and endless war (fought on religious and political grounds). Thinkers such as Montaigne urge the virtue of toleration (Catholics and Lutherans in Germany; Jews in Amsterdam). Missing is a philosophical framework in which individual liberty (esp. freedom of conscience) can be 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 first problem but has nothing to say about the second. Hobbes goes further in challenging traditional theological assumptions about human beings, and claiming that a stable political solution can be found, based on a revised scientific understanding of human beings.
Hobbes Ethical Theory Given Hobbes starting points (materialism, empiricism, nominalism), he is led to a radically new understanding of ethics as the science of passions. (ch. 6; see ch. 4 [24]) Passions are just motions of matter: the small beginnings 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 endeavor toward something is appetite or desire ; the endeavor away from something is aversion. The other passions are defined in terms of these.
The Relativity of Good and Evil But whatsoever is the object of any man s appetite or desire that is it which he for his part calleth good; and the object of his hate and aversion, evil; and of his contempt, vile and inconsiderable. For these words of good, evil, and contemptible are ever used with relation to the person that uses them, there being nothing simply and absolutely so, nor any common rule of good and evil to be taken from the nature of the objects themselves, but from the person of the man, where there is no commonwealth, or, in a commonwealth, from the person that representeth it, or from an arbitrator or judge whom men disagreeing shall by consent set up and make his sentence the rule thereof.