Mind and body in early modern philosophy

DOI: 10.4324/9780415249126-V043-1
Version: v1,  Published online: 2016
Retrieved December 12, 2018, from

2. Early critics of Descartes

When Descartes’s Meditations were first published, they were accompanied by several sets of Objections from other philosophers, as well as Descartes’s Replies. Thomas Hobbes, later to become famous as a political philosopher, was the author of the Third Set of Objections (Hobbes [1641] 1984). Hobbes suggested, in contrast to Descartes, the possibility of materialism about the human mind: the thing that has reason (see Materialism in the philosophy of mind). His materialist account relies upon the powers of language in order to explain our reasoning ability. Our use of language does not, Hobbes thought, require us to have any mental faculty over and above the imagination – certainly not the sort of incorporeal rational faculty that Descartes thought we possessed, with its ability to have clear and distinct intellectual perception of the natures of things. Instead,

reasoning will depend on names, names will depend on the imagination, and imagination will depend … merely on the motions of our bodily organs; and so the mind will be nothing more than motion occurring in various parts of an organic body.

(Hobbes [1641] 1984: 126)

Pierre Gassendi was a French contemporary of Descartes’s, who had been professor of philosophy at the university of Aix-en-Provence, France and would later be professor of mathematics at the Collège Royal in Paris. He was the author of the Fifth [Set of] Objections to the Meditations (Gassendi [1641] 1984). Later, he wrote a further book containing objections to Descartes’s Replies (Gassendi 1644). Of particular note here is the way in which Descartes and Gassendi disagreed about how we ought to investigate the nature of the mind. Descartes thought that rational reflection and clear and distinct perception could lead us to knowledge of the mind’s essence, which is its principal attribute: thinking. Gassendi thought that this was the wrong picture of what we need to do to achieve ‘the kind of knowledge which is superior to common knowledge’ (Gassendi [1641] 1984: 193). He compared Descartes’s investigation of the mind to an investigation of wine. To say that the mind is a thinking thing is like saying ‘wine is a liquid thing, which is compressed from grapes, white or red, sweet, intoxicating’ (Gassendi [1641] 1984: 193). This kind of superficial description is not what we are after. Rather, to have superior knowledge about the wine, you want to ‘explain its internal substance, showing how it can be seen to be manufactured from spirits, tartar, the distillate, and other ingredients mixed together in such and such quantities and proportions’ (Gassendi [1641] 1984: 193). That is, you want to investigate it chemically. And, analogously, Gassendi said, to understand the mind we want ‘a kind of chemical investigation’ of it (Gassendi [1641] 1984: 193), which Descartes failed to provide – and which his method is perhaps not suited to provide. Later, Simon Foucher would also criticize Descartes’s claim to know the essences of mind and body, from a broadly sceptical perspective (see Foucher, S.).

A third early critic of Descartes was Princess Elisabeth of Bohemia, who corresponded with him in the 1640s. Early in their correspondence, she asked Descartes about his views about mind and body, and in particular about how they were related to each other. In the Meditations, Descartes had emphasized that there is a peculiarly close relationship between the human mind and body. He had denied that we should think of the mind and body on the model of a sailor in a ship. On that model, there is causal influence in both directions, and the mind observes and controls the body. But that, Descartes thought, was not a close enough relationship: mind and body are ‘very closely joined and, as it were, intermingled’ (Descartes [1641] 1984: 56). Nevertheless, one might still ask what exactly this relationship is. And, as Elisabeth did, one might ask how they are able to interact at all. Bodies, in Descartes’s picture of the physical world, are affected by being pushed by other bodies that they are in contact with. But it seems that an incorporeal, non-extended mind is the wrong sort of thing to push on anything. So how, Elisabeth asked, can the Cartesian mind affect the body (Elisabeth [1643] 2007)?

Replying to Elisabeth, Descartes sketched an apparently new theory, involving three ‘primitive notions that are like originals on the pattern of which we form all our other knowledge’ (Descartes [1643] 2007: 65). In understanding the body alone, we use the notion of extension. In understanding the soul alone, we use the notion of thought. But we also, Descartes says, have a third notion, of their union. Trying to understand mind–body interaction using the notion of extension, and the model of bodies pushing on each other, is doomed to failure. But we have this additional notion of the union, involving the power of minds to act on bodies. We can understand those interactions well enough, Descartes thinks, and do so quite naturally, as long as we do not try to force them into the other model (see also Mental causation §2).

Citing this article:
Duncan, Stewart. Early critics of Descartes. Mind and body in early modern philosophy, 2016, doi:10.4324/9780415249126-V043-1. Routledge Encyclopedia of Philosophy, Taylor and Francis,
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