Quote
The major line of philosophers rejected Kant’s “noumenal” world quite speedily, but they accepted his “phenomenal” world and carried it to its logical consequences: the view of reality as mere appearance; the view of man’s conceptual faculty as a mechanism for producing arbitrary “constructs” not derived from experience or facts; the view of rational certainty as impossible, of science as unprovable, of man’s mind as impotent–and above all, the equation of morality with selflessness. They rejected the root or cause of Kant’s system, but accepted all of its deadly effects.
-Ayn Rand (For the New Intellectual, 32; Kndl ed.)
If the majority of philosophers rejected Kant’s “noumenal” realm, they have left out an important aspect of his philosophy - the source of all phenomena. Because even if the noumenal is unknowable, it is, for Kant, the grounds for phenomena beyond the senses. It doesn’t matter if the senses modify, what matters is that Kant posited the noumenal’s existence.
It is THIS that is the problem with modern philosophy - not the acceptance of Kant’s philosophy, but its rejection of the ground of appearances (or phenomena).
Logically, Rand committed the Fallacy of the Consequent in that quote. Because she focused on the alleged consequences of Kant’s philosophy rather than specifically on the (incorrect) rejection of the noumenal realm by post-Kantian philosophers, which is my point.
Despite the inherent unknowability of the noumenal, its positing serves as the foundation for understanding the empirical origins of phenomena, a notion often overlooked in contemporary philosophical discourse.
The empiricist often confuses Kant’s form of Idealism with those that infer the existence of an external world from the matter of appearances (mental states). But Kant did not infer it, he wholeheartedly accepted its existence. He only inferred the existence of the thing-in-itself (or noumenon), not the existence of external things, which he accepted.
The noumenal is the ground of experience. Without it, there is no perception, nothing to perceive. Kant never denied the ground of perception, only that it is knowable in itself, that is, by somehow going outside of your consciousness to know it directly without your senses.
The noumenal is posited to exist as the ground of perception, of something for the senses to sense. The only way to know it directly would be to somehow go outside of your senses.
Simple as that.