SUBJECT AND PREDICATE

[B149] Kant defines various types of judgments in terms of the relation of the subject to the predicate (e.g., in analytic judgment the predicate is "contained within" the subject, in tautologies the subject and predicate are simply identical). He also interestingly defines substance as a subject and non-predicate. On the one hand, Kant defines substance as "something which can exist as subject and never as mere predicate". [A348] On the other hand, in the Paralogism in A, Kant holds that the self is "the subject of all my possible judgments", but dismisses the rational psychologist's inference that "therefore I, as thinking being (soul), am substance". Why is this? [A400] "The bare concept of substance (supplied by the understanding) contains nothing beyond the requirement that a thing be represented as being subject in itself, and not in turn predicate of anything else....from this source we learn nothing whatsoever" about "the knowledge of the soul for which we are seeking."