2. Kant distinguishes a subjective and an objective deduction in his investigation of the problem of knowledge.
a. It is the business of subjective deduction to discover the forms of our intuition and reflection. These forms represent what is constant and universal,—that which is capable of maintaining its identity, even though the qualitative content, the matter, changes. They are discovered by a psychological analysis which distinguishes between the changeable and the permanent. In this way we discover extension (space) and succession (time) as constant elements of sensory intuition, magnitude and causality as constant elements of thought. The Forms of intuition are forms of our receptivity. As a matter of fact they too are a kind of synthesis, a combining together; but at this stage our own activity does not yet attain the prominence that it does in thought; here the only concern is the arrangement of the sensations in immediate intuition. We develop a higher level of activity whenever we place these intuitional images in relation to each other. This function is more fully conscious than the involuntary process of intuition. Kant calls it apperception. Whenever we pass from a given spatial or temporal intuition to another, we are trying to affect our own inner unity, in the fact that we combine together the antecedent and consequent in a definite manner. Thus, e. g. I know a line only when I draw it, i. e. when I combine its several parts according to a definite law. Or, e. g. I know a fact, e. g. the freezing of water, only when I am in position to combine the antecedent state (the water in liquid form) with its consequent according to a definite law.
Kant believes that he has thus discovered a method which proves the necessity of a certain number of con-
