In the Introduction, Kant claims to have discovered a new distinction between kinds of judgement, and a new class of judgements which neither rationalism nor empiricism can account for. The distinction is between what Kant calls ‘analytic’ and ‘synthetic’ judgements, and the judgements which are problematic for rationalism and empiricism are ‘synthetic a priori’ judgements. The task of the Critique is restated as that of finding an answer to the question of how synthetic a priori judgements are possible (B19). Kant attaches such importance to this problem that he says that the unhappy state of metaphysics is due entirely to the fact that it has never previously been considered (B19). (In his later writings Kant formulates the fundamental problems of ethics and aesthetics too in terms of synthetic a priority.) The Introduction contains, therefore, Kant’s opening move against rationalism and empiricism. It is designed to clarify significantly the problem of metaphysics and even advance the case for its possibility.