Chapter XXXIV: Section I: Ideas in General1386

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]

Kant[1399] appends the following ‘Stufenleiter’ (ladder-like) arrangement of titles for the various kinds of representation. Representation (_Vorstellung_) is the term which he substitutes for the Cartesian and Lockian employment of the term idea, now reserved for use in its true Platonic meaning. To entitle such a representation as that of red colour an idea is, in Kant’s view, an intolerable and barbaric procedure; that representation is not even a concept of the understanding.

Representation {
(_Vorstellung_, { Perception =
_Repraesentatio_) { Representation --->
with or without { with consciousness
consciousness {

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{ Idea (_Idee_) or concept of
{ Reason [formed, Kant here
{ says, from notions, but
{ Pure { transcending the possibility
{ { of experience].
{ Objective = { Concept { { Notion (_notio_) [= category
{ Knowledge { (_Begriff_) { { of understanding].
-->{ (_Erkenntnis_) { { Empirical.
{ { Intuition (_Anschauung_).
{ Subjective = Sensation (_Empfindung_).