Is Kant's Distinction between Noumenon and Phenomena one of knowledge (proven) or belief (postulated)?

Question

Kant distinguishes between between the thing for me and the thing in itself in his Critique. Because we tend to posit apriori categories into our experience, we cannot get at objective reality but only appearances. But, isn't Kant contradicting himself then? He says we can't know reality, while he believes that in reality there is really a distinction between Noumenon and Phenomena. How can Kant prove anything about reality or even doubt reality if he rejects all knowledge of objective reality? Is this distinction then viewed by Kant as a postulate, just like he postulates the existence of God to explain morality in his Critique of Practical Reason? Since he can't prove that there is a distinction in reality between Noumenon and Phenomena, maybe he postulates (but doesn't prove) this difference in order to explain how we arrive at concepts like causality that Hume dealt with in his Treatise.

I am a little confused :).

Thank you for your help in advance and God Bless you.

Answer 1

Hi Paul,

Your question is right to ask how Kant establishes the difference between the phenomena (things we can know about form appearances) and the noumena (things in themselves).

However, if you follow his argument, you find that 1.) for him, the phenomena are precisely what give us our sense of the objective, empirical reality, and 2.) the noumena are something like the empty condition of certain objective presentations, but which necessarily transcend our understanding as things in themselves. For Kant, there is no realism besides an apparent realism.

But what about the noumena? Aren't these real? And if they are real, and somehow responsible for the phenomena, aren't they what constitute "objective reality." For Kant, the answer is "no." An object for Kant is something that can be given in representation, and which can be the basis for judgments and predications.

Let me give you a quick example. For Kant, the flame is objectively the cause of heat because our concept of cause is a priori necessary in the synthesis of the representation of the appearing relationship. But what is the basis of the relationship on the side of the object outside of cognition? The answer to such a question cannot be known, but only thought about in speculation. It's this move to speculation about transcendent (not transcendental) conditions for the experience of objective relations that leads us into the noumena. In fact, the noumena is just a name for that which is necessarily taken as the possible transcendent basis for all validly conceived objectivities. But to say anything about the noumena (to render a judgment about them as though they could be predicated under a concept) is a mistake of reason.

One more interesting thing about the noumena is that they are closely related to the transcendent ideas that become regulative of different systems of practice. That is, various transcendent ideas are assumed (I suppose we could say "postulated as principles") are necessary for our knowledge of matters of practical reason, e.g., the form of freedom is necessary to understand morality within the critique of pure practical reason.

Does this help to answer your question? If not, we can always talk more about it.