Kant anchors his argument on the difference between pure and empirical knowledge on the premise that human experience is the cornerstone of knowledge. He contends that it is impossible to understand anything before experiencing it. However, he recognizes that experience is not the source of all human knowledge, but just a starting point— “the first instruction.” Accordingly, peoples’ impressions and their personal repositories of knowledge may also influence their understanding, which is an indication of their ability to differentiate between their knowledge and raw data.
Kant wonders whether there is knowledge that exists independent of experience, a priori, compared to that which develops through experience, a posteriori, and poses the question whether such a distinction exists. The former is pure knowledge, being that it is independent of all experience, while the latter is empirical in nature as it derives from experience. The author discusses a method for differentiating between these two forms of knowledge. He identifies necessity and strict universality as certain criteria for pure knowledge, which he interprets as indication of a special source of knowledge. Humans possess repositories of knowledge that are necessary and universal, therefore, pure. He asserts that pure knowledge is integral to developing experience as it facilitates certainty as guiding rules.
Kant proceeds to identify a philosophical gap in the form of the lack of a means to determine the possibility, principles, and scope of pure knowledge. There are situations where experience becomes inadequate, thereby requiring reason to supplement human knowledge. He identifies metaphysics as the realm where reason necessarily takes precedence over experience owing to the latter’s inadequacy to facilitate interrogation of abstract concepts. However, Kant emphasizes the need to engage in such abstract enquiries cautiously by interrogating the origins of the a priori knowledge that informs them. He notes that reason enables people to engage in analysis that results in the development of knowledge.
He turns to an evaluation of the difference between analytic and synthetic judgments and explains that the presence or absence of an identity between the subject and the predicate is the determining factor. Hence, a judgement is synthetic where the connection is without identity. Synthetic a priori judgements are embodied as principles of reason in all theoretical sciences. The author refers to judgements in mathematics, physics, and metaphysics as apt examples of synthetic judgements. They satisfy the elements of necessity that does not derive from experience and strict universality. However, the possibility of synthetic judgements constitutes a problem for pure reason, thus, provides the basis and justifications for developing a special science called a ‘critique of pure reason.’