The distinction between the analytic and the synthetic involved novel terminology, although similar distinctions can be found in earlier philosophers. Aquinas, inspired by Boethius, defines a ‘self-evident’ proposition as one in which the ‘predicate is contained in the notion of the subject’, and a similar idea is to be found in Leibniz. What is original, however, is Kant’s insistence that the two distinctions (between the a priori and the a posteriori, and between the analytic and the synthetic), are of a wholly different nature.
