phenomena. "That external objects are real as representations"
Berkeley had never disputed.]

On the basis of the inseparability of sensibility and understanding the
ideal of knowledge--an extension of knowledge to be attained by _a priori_
means (p. 333)--experiences a remarkable addition in the position that the
rational synthesis thus obtained must be a knowledge of reality, must be
applied to matter given in intuition. To the question, "How are synthetic
judgments _a priori possible_?" is joined a second equally legitimate
inquiry, "How do they become _objectively valid_, or applicable to objects
of experience?" The principle from which their validity is proved--they are
applicable to objects of experience because _without them experience would
not be possible_, because they are _conditions of experience_--like the
criterion of apriority (strict universality and necessity), is one of the
noetic assumptions of the critical theory.[1]

[Footnote 1: Cf. Vaihinger, _Kommentar_, i. pp. 425-430.]

Inasmuch as its investigation relates to the conditions of experience the
Kantian criticism follows a method which it itself terms _transcendental_.
Heretofore, when the metaphysical method had been adopted, the object had
been the suprasensible; and when knowledge had been made the object of
investigation, the method followed had been empirical, psychological. Kant
had the right to consider himself the creator of noetics, for he showed it
the transcendental point of view. Knowledge is an object of experience, but
its conditions are not. The object is to explain knowledge, not merely to
describe it psychologically,--to establish a new science of knowledge from
principles, from pure reason. That which lies beyond experience is
sealed from our thought; that which lies on this side of it is still
uninvestigated, though capable and worthy of investigation, and in
extreme need thereof. Criticism forbids the _transcendent_ use of reason
(transcending experience); it permits, demands, and itself exercises the
_transcendental_[1] use of it, which explains an experiential object,
knowledge, from its conditions, which are not empirically given.

[Footnote A: Kant applies the term _transcendental_ to the knowledge (the
discovery, the proof) of the _a priori_ factor and its relation to objects
of experience. Unfortunately he often uses the same word not only to
designate the _a priori_ element itself, but also as a synonym for
transcenden