Thing in Itself
Rene Descartes’ method of doubt provides the argument for the existence of the mind, which is, perhaps, the cornerstone of his philosophy. Immanuel Kant, on the other hand, treats ‘reason’ or rationality as a crucial factor in his philosophical accounts. With regard to Descartes, the concept of the ‘thing in itself’ can be analyzed in terms of his method of hyperbolic doubt, such that he cannot doubt that he exists. As for Kant, the concept of the ‘thing in itself’ can best be understood in terms of his treatment on the distinction between the noumenal or rational world and the spatiotemporal world.
Descartes method of doubt tells us that the only thing that an individual can be sure of is his existence, such that the fact that one can begin to doubt one’s existence is proof that there must be that something which ‘doubts’. Given that there is a looming ‘doubt’, it cannot be questioned that there is indeed something that doubts, and that ‘doubting’ thing is a thinking thing. At the least, the attribute of being able to doubt makes Descartes to believe that he exists for if he did not then he would not have doubted his existence in the first place (Garber, p. 226).
Hence, it can be said that the concept of the ‘thing in itself’ in terms of Descartes’ philosophy stands as something which claims that there is a material, external world outside of the mind. Things by themselves, then, would be as they are whether or not the mind is able to grasp these external entities. Descartes is also known for his belief in the mind and body dualism, such that the mind is a separate entity from the corporeal or physical body. In its entirety, it can be said that Descartes is espousing the idea that the thing in itself is one which is in the external world, although it can also be the thinking thing, or the mind. As for the objects external from the mind, these objects are things in themselves for the reason that the mind is able to acquire knowledge through them, specifically through a deductive inquiry into their nature and essence.
Immanuel Kant, on the other hand, espouses the idea of noumenon as synonymous with the ‘thing in itself’, which is that the noumenal realm is the realm which is not accessible precisely because of the limits of the rationality. From here, it can be said that Kant acknowledges that there are indeed ‘things in themselves’ only that human reason is unable to completely grasp these ‘things in themselves’ in the noumenal realm. Kant’s noumenon is to be distinguished with his concept of the phenomenon. On one hand, the phenomenon is that which is grasped by our sensory perceptions or that which is perceived. On the other hand, the noumenon is the actual object which gives the perceived phenomenon (Clarke, p. 55).
In order to make the distinction clearer, one can resort to the example of, say, the object ‘pencil’. In terms of Kant’s philosophy, the actual ‘pencil’ is the actual object and the essence of the actual ‘pencil’ cannot be grasped even through our reason and sensory perceptions. On the contrary, what we can only be able to grasp is the phenomenon that emanates from the actual pencil. That is, our senses are only able to acquire the various attributes of the actual pencil such as size, color, shape and texture among many others. We are never able to grasp the essence of the actual pencil, only the ‘properties’ or the phenomenon that come from it.
The contrast between Kant and Descartes’ treatment of the thing in itself resides on their basis for which upon the ‘thing in itself’ can be accessed. Apparently, both Kant and Descartes give a substantial consideration for the mind or reason in trying to understand the material world and the rest of the objects as ‘things in themselves’. Thus, once the mind or reason is deprived of its role in discerning the objects around it, or if the mind or reason is removed from the task of contemplating the ‘thing in itself’, there is strong reason to believe, as far as Kant and Descartes are concerned, that any effort to philosophize about these things would be futile.
More importantly, the distinction between Kant and Descartes resides on the fact that Kant is inclined to believe that we cannot entirely comprehend the essence of any ‘thing in itself’ and that only the phenomenon can be accessed by reason and our sensory perceptions. On the other hand, Descartes does not explicitly make a claim denying the reason of the ability to comprehend the essence of objects. On the contrary, Descartes tells us that we should rely on the deductive process through the minds in our quest for understanding the world of objects and less on the sensory perceptions for they may simply give us a limited account of the world.
In conclusion, it can be said that the distinction between Kant and Descartes in terms of their take on the concept of the ‘thing in itself’ differs solely on whether or not the noumenon or the actual objects are accessible. Both Kant and Descartes agree on the substantial function and purpose of reason in discerning the world or at least the ‘thinking thing’ in the words of Descartes. Without the mind, one can hardly arrive at a substantial thought on the world, or that there can be no ‘hyperbolic doubting’ to begin with. The use of the mind is significant in both the philosophies of Kant and Descartes, especially in their analysis of the concept of the ‘thing in itself’.
Garber, Daniel. “Descartes and Method in 1637.” PSA: Proceedings of the Biennial Meeting of the Philosophy of Science Association 2 (1988): 226.
Clarke, Michael. “Kant’s Rhetoric of Enlightenmentkant’s Rhetoric of Enlightenment.” The Review of Politics 59.1 (1997): 55.