“All knowledge demands a concept, though that concept may be quite imperfect or obscure. But a concept is always, as regards its form, something general which serves as a rule. The concept of body, for instance, as the unity of the manifold which is thought through it, serves as a rule to our knowledge of outer appearances.... It necessitates in the perception of something outside us the representation of extension, and therewith the representations of impenetrability, form, etc.”[886] So far the deduction still moves on the empirical level. When Kant, however, proceeds to insist[887] that this empirical postulate itself rests upon a transcendental condition, the argument is thrown into complete confusion, and the reader is bewildered by the sudden anticipation of one of the most difficult and subtle conclusions of the objective deduction. The same confusion is also caused throughout these sections as a whole by Kant’s description of the various syntheses as being transcendental.[888] They cannot properly be so described. The concepts referred to as unifying the syntheses, and the self-consciousness which is proved to condition the syntheses, are all empirical. They present themselves in concrete form, and presuppose characteristics due to the special contingent nature of the given manifold; as Kant states in so many words in the second edition. “Whether I can become _empirically_ conscious of the manifold as simultaneous or as successive depends on circumstances or empirical conditions. The empirical unity of consciousness, through association of representations, therefore itself relates to an appearance, and is wholly contingent.”[889] The argument in these preliminary stages of the subjective deduction, in so far as it is employed to yield proof that all consciousness involves the unity of concepts and the unity of self-consciousness, is independent of any reference to the categories, and consequently to transcendental conditions. In accordance with the plan of exposition above stated, we may now pass to the objective deduction. OBJECTIVE DEDUCTION AS GIVEN IN THE FIRST EDITION