Hobbes was a materialist and so opposed to Descartes, who was a dualist. In plain terms, a materialist believes there is only one kind of thing: matter or bodies. Dualists believe there are two kinds of thing: matter and minds (or spirits or souls, the words are used interchangeably). Minds (spirits, souls) are immaterial, meaning they do not have the properties of matter, such as having extension and being subject to the laws of physics.
Today’s reading has Hobbes’s objections to Descartes’s Meditations and the opening chapters of Hobbes’s own book Leviathan. In them, he makes objections to dualist views and sketches out his own materialist explanation of how the mind works.
Hobbes grants Descartes’s argument that if he knows he is thinking he can infer that he exists. But he insists that the thinking thing that exists has to be a body (or “corporeal”). The crucial assumption comes in the second to last sentence: “we cannot separate thought from the matter that thinks” (Hobbes [1642] 2019, 77L).
Descartes, in response, says that subjects of acts do not have to be corporeal. They can be substances or “metaphysical matter” (Descartes [1642] 2019, 77R).
Descartes says that we do not know the thinking substance directly; we only know about it through its acts. Then he makes parallel cases for what features belong together as bodies and minds, respectively, and then explaining why they are grouped together, again, respectively. I have made notes in the passage to show how the grouping works.
[What for bodies -mjg] There are certain acts which we call “corporeal,” such as size, shape, motion, and all the other properties that cannot be thought of apart from their being extended in space; and the substance in which they inhere we call “body.” [Why for bodies -mjg] Nor is it possible to imagine that it is one substance that is the subject of shape and another substance that is the subject of movement from place to place, and so on, since all these acts have in common the one feature of being extended. [What for minds -mjg] In addition, there are other acts, which we call “cogitative” (such as understanding, willing, imagining, sensing, and so on), all of which have in common the one feature of thought or perception or consciousness; [why for minds -mjg] but the subject in which they inhere we say is “a thing that thinks” or a “mind,” or any other thing we choose provided we do not confuse it with corporeal substance, since cogitative acts have no affinity to corporeal acts, and thought, which is the feature they have in common, is utterly different in kind from extension, which is the feature the others have in common. (Descartes [1642] 2019, 78L). (notes in brackets added)
This is from the Introduction to Leviathan. In the first part of this passage, Hobbes articulates his mechanistic view of human beings in particularly vivid language. In the second part, he describes the state as an artificial man.
Nature (the art whereby God hath made and governs the world) is by the art of man, as in many other things, so in this also imitated, that it can make an artificial animal. For seeing life is but a motion of limbs, the beginning whereof is in some principal part within; why may we not say, that all automata (engines that move themselves by springs and wheels as doth a watch) have an artificial life? For what is the heart, but a spring; and the nerves, but so many strings; and the joints, but so many wheels, giving motion to the whole body, such as was intended by the artificer? Art goes yet further, imitating that rational and most excellent work of nature, man. For by art is created that great leviathan called a commonwealth, or state, (in Latin civitas) which is but an artificial man; though of greater stature and strength than the natural, for whose protection and defence it was intended; and in which, the sovereignty is an artificial soul, as giving life and motion to the whole body; the magistrates, and other officers of judicature and execution, artificial joints; reward and punishment (by which fastened to the seat of the sovereignty every joint and member is moved to perform his duty) are the nerves, that do the same in the body natural; the wealth and riches of all the particular members, are the strength; salus populi (the people’s safety) its business; counsellors, by whom all things needful for it to know are suggested unto it, are the memory; equity, and laws, an artificial reason and will; concord, health; sedition, sickness; and civil war, death. Lastly, the pacts and covenants, by which the parts of this body politic were at first made, set together, and united, resemble that fiat, or the let us make man, pronounced by God in the creation. (Hobbes [1651] 2019, 120–21)
If you are looking at comparing Hobbes and Descartes, for example, it is worth knowing that Hobbes thinks that all living animals are automata. Descartes thought that was true only of non-human animals.
The last sentence describes us as being like God because we can create an artificial man: the state. Hobbes is famous for describing human nature in unflattering terms. Keep in mind that he also thought we were like God. All of the other animals live in their natural condition. Human beings do not.
You might know of Leviathan as a book in political philosophy. But it starts with a materialist account of the mind. What Hobbes is trying to show is that the mental phenomena that we are familiar with can be explained as matter in motion.
He covers three topics:
Sensation is a motion conveyed by the senses. Imagination is the continued motion in the brain after the cause of the initial sensation is gone; Hobbes calls it “decaying sense.” That is how we think about things that we are not immediately looking at. Trains of imagination are more complex thoughts.
In the chapter on imagination, look for an answer to the dream argument. Also, Hobbes has interesting remarks about animals and how they understand language. It seems to me that Hobbes partly agrees with Descartes here and partly disagrees with him (see Hobbes [1651] 2019, 125R; compare Descartes [1637] 2019, 33–34).
When we get to trains of imagination, the materialist story largely fades away. Hobbes is just talking about ideas that seem related to one another, such as pennies and Judas’s betrayal of Jesus Christ, rather than finding a physical explanation of why one idea leads to another (Hobbes [1651] 2019, 125–26).