In his book on Hegel, Charles Taylor summarizes the crique Hegel brings against Descartes. For Hegel, Descartes aims to unite thought and external reality, but the manner he uses to do that ends up losing both. The cogito is an “assertion of an immediate identity between thought and being,” an identity that is “immediate, because as Descartes insists there is not even an inference here.” But the thought is pure thought, abstracted from any particular content: “none of the contents of my thought are englobed in this certainty, just the fact of thinking itself, with the inseparable concomitant of existing.” Thus, Descartes arrives at certainty only by emptying the knowledge of which he is certain of all particular content.
The result of this procedure is that Descartes is incapable of uniting thought and being, his original aim: “Because their unity in the cogito is simply immediate, combining merely abstract thought with being, their true unity cannot be portrayed, and over against the being-which-is-thought, the cogito, is another mode of being which is radically non-thought, matter.”
But the Cartesian move eventually loses matter. Matter’s essence is extension, a “property of matter which can be derived in pure thought, and not like other properties, smell, colour, etc., merely by the senses.” Pure matter in modern philosophy is “so much a vision of thought [as opposed, among other things, to being a product of sense] that it constantly belies the role it is made to play.” Descartes and others appear to be radical materialists, but the matter they talk about slips into spirit: “this pure matter is so rarefied by thought that explanations in terms of it might just as well be seen as having the opposite sense, as giving a basic ontological role to the spiritual, to thought.”
In short, “because the notion of thought is abstract and without rich internal development, so is the notion of matter.” Matter is extension and motion, the two aspects of matter that can be arrived at within the mind, without actual observation of reality. This leads to a mechanical understanding of extra-mental reality, and to the extent that Descartes is the “father of mechanism,” he is for that reason incapable of understanding life: “those domains of philosophy which can be called philosophy of spirit: psychology, politics, etc., are ill-developed in this thought.”
Peter Leithart
Peter J. Leithart is President of Theopolis Institute. He is the author of numerous books on theology, literature, and culture, including Theopolitan, Defending Constantine, and Baptized Body.
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