III. Hence, in positing matter and force as the content of sensuous knowing, they unwittingly assert mediation to be the content of immediateness.
The decline of this period of science results from the perception of the contradiction involved. Kant was the first to show this; his labors in this field may be summed up thus:
The universal and necessary is not an empirical result. (General laws cannot be sensuously perceived.) The constitution of the mind itself, furnishes the ground for it:—first, we have an a priori basis (time and space) necessarily presupposed as the condition of all sensuous perception; and then we have categories presupposed as the basis of every generalization whatever. Utter any general proposition: for example the one above quoted—“all is matter and force”—and you merely posit two categories—Inherence and Causality—as objectively valid. In all universal and necessary propositions we announce only the subjective conditions of experience, and not anything in and for itself true (i. e. applicable to things in themselves).
At once the popular side of this doctrine began to take effect. “We know only phenomena; the true object in itself we do not know.”
This doctrine of phenomenal knowing was outgrown in Germany at the commencement of the present century. In 1791—ten years after the publication of the Critique of Pure Reason—the deep spirit of Fichte began to generalize Kant’s labors, and soon he announced the legitimate results of the doctrine. Schelling and Hegel completed the work of transforming what Kant had left in a negative state, into an affirmative system of truth. The following is an outline of the refutation of Kantian scepticism:
I. Kant reduces all objective knowledge to phenomenal: we furnish the form of knowing, and hence whatever we announce in general concerning it—and all that we call science has, of course, the form of generality—is merely our subjective forms, and does not belong to the thing in itself.
II. This granted, say the later philosophers, it follows that the subjective swallows up all and becomes itself the universal (subject and object of itself), and hence Reason is the true substance of the universe. Spinoza’s substance is thus seen to become subject. We partake of God as intellectually seeing, and we see only God as object, which Malebranche and Berkeley held with other Platonists.
1. The categories (e. g. Unity, Reality, Causality, Existence, etc.) being merely subjective, or given by the constitution of the mind itself—for such universals are presupposed by all experience, and hence not derived from it—it follows:
2. If we abstract what we know to be subjective, that we abstract all possibility of a thing in itself, too. For “existence” is a category, and hence if subjective, we may reasonably conclude that nothing objective can have existence.
3. Hence, since one category has no preference over another, and we cannot give one of them objectivity without granting it to all others, it follows that there can be no talk of noumena, or of things in themselves, existing beyond the reach of the mind, for such talk merely applies what it pronounces to be subjective categories, (existence) while at the same time it denies the validity of their application.