A Commentary to Kant's 'Critique of Pure Reason'

by Norman Kemp Smith

Kant connects his use of the term Idea with the meaning in which it is employed by Plato. He urges upon all true lovers of philosophy the imperative need of rescuing from misuse a term so indispensable to mark a distinction more vital than any other to the very existence of the philosophical disciplines.

”[For Plato] Ideas are the archetypes of the things themselves, and not, like the categories, merely keys to possible experiences. In his view they issued from the Supreme Reason, and from that source have come to be shared in by human Reason.... He very well realised that our faculty of knowledge feels a much higher need than merely to spell out appearances according to a synthetic unity, in order to read them as experience. He knew that our Reason naturally exalts itself to forms of knowledge which so far transcend the bounds of experience that no given empirical object can ever coincide with them, but which must none the less be recognised as having their own reality and which are by no means mere fictions of the brain.”[1387]

Plato found these ideas chiefly, though not exclusively, in the practical sphere. When moral standards are in question, experience is the mother of illusion.

“For nothing can be more injurious or more unworthy of a philosopher than the vulgar appeal to so-called adverse experience. Such experience would never have existed at all, if those institutions had been established at the proper time in accordance with Ideas, and if Ideas had not been displaced by crude conceptions which, just because they have been derived from experience, have nullified all good intentions.”[1388]

Even in the natural sphere Ideas which are never themselves adequately embodied in the actual must be postulated in order to account for the actual. Certain forms of existences “are possible only according to Ideas.”

“A plant, an animal, the orderly arrangement of the cosmos—probably, therefore, the entire natural world—clearly show that they are possible only according to Ideas, and that though no single creature in the conditions of its individual existence coincides with the Idea of what is most perfect in its kind—just as little as does any individual man exactly conform to the Idea of humanity, which he actually carries in his soul as the archetype of his actions—yet these Ideas are none the less completely determined in the Supreme Understanding, each as an individual and each as unchangeable, and are the original causes of things. But only the totality of things, in their interconnection as constituting the universe, is completely adequate to the Idea.”[1389]

Though Kant avows the intention of adapting the term Idea freely to the needs of his more Critical standpoint, all these considerations contribute to the rich and varied meanings in which he employs it.

Reflexionen and passages from the Lectures on Metaphysics may be quoted to show the thoroughly Platonic character of Kant’s early use of the term, and to illustrate its gradual adjustment to Critical demands.

“The Idea is the unity of knowledge, through which the manifold either of knowledge or of the object is possible. In the former, the whole of knowledge precedes its parts, the universal precedes the particular; in the latter, knowledge of the objects precedes their possibility, as e.g. in [objects that possess] order and perfection.”[1390] “That an object is possible only through a form of knowledge is a surprising statement; but all teleological relations are possible only through a form of knowledge [i.e. a concept].”[1391] “The Idea is single (individuum), self-sufficient, and eternal. The divinity of our soul is its capacity to form the Idea. The senses give only copies or rather apparentia.”[1392] “As the Understanding of God is the ground of all possibility, archetypes, Ideas, are in God.... The divine Intuitus contains Ideas according to which we ourselves are possible; cognitio divina est cognitio archetypa, and His Ideas are archetypes of things. The [corresponding] forms of knowledge possessed by the human understanding we may also entitle (in a comparative sense) archetypes or Ideas. They are those representations of our understanding which serve for judgment upon things.”[1393] “Idea is the representation of the whole in so far as it necessarily precedes the determination of the parts. It can never be empirically represented, because in experience we proceed from the parts through successive synthesis to the whole. It is the archetype of things, for certain objects are only possible through an Idea. Transcendental Ideas are those in which the absolute whole determines the parts in an aggregate or as series.”[1394] “The pure concepts of Reason have no exemplaria; they are themselves archetypes. But the concepts of our pure Reason have as their archetypes this Reason itself and are therefore subjective, not objective.”[1395] “The transcendental Ideas serve to limit the principles of experience, forbidding their extension to things in themselves, and showing that what is never an object of possible experience is not therefore a non-entity [Unding], and that experience is not adequate either to itself or to Reason, but always refers us further to what is beyond itself.”[1396] “The employment of the concept of understanding was immanent, that of the Ideas as concepts of objects is transcendent. But as regulative principles alike of the completion and of the limitation of our knowledge, they are Critically immanent.”[1397] “The difficulties of metaphysics all arise in connection with the reconciling of empirical principles with Ideas. The possibility of the latter cannot be denied, but neither can they be made empirically intelligible. The Idea is never a conceptus dabilis; it is not an empirically possible conception.”[1398]