Hume's skepticism, more particularly his technical distinction between a priori and a posteriori propositions or statements, awakened Kant from his dogmatic slumber, and provided a basis for treating the question of whether, and how metaphysics is possible. Kant said that it was the influence of David Hume (awakening from the dogmatic slumber), which had turned his mind to the new fields of speculative philosophy. One can identify two possible versions of Humean influence on Kant. The first is connected with the conception of the “skeptical method”, to which Kant adhered since about 1765, and the second is the true awakening which took place in the summer of 1771.1 In acknowledging the profound influence of Hume in his speculative philosophy, Kant asserts: I openly confess, the suggestion of David Hume was the very thing, which many years ago first interrupted my dogmatic slumber, and gave my investigations in the field of speculative philosophy quite a new direction. I was far from following him in the conclusions at which he arrived by regarding, not the whole of his problem, but a part, which by itself can give us no information. If we start from a well-founded, but undeveloped, thought, which another has bequeathed to us, we may well hope by continued reflection to advance farther than the acute man, to whom we owe the first spark of light. I therefore first tried whether Hume's objection could not be put into a general form, and soon found that the concept of the connection of cause and effect was by no means the only idea by which the understanding thinks the connection of things a priori, but rather that metaphysics consists altogether of such connections. But as soon as I had succeeded in solving Hume's problem not merely in a particular case, but with respect to the whole faculty of pure reason, I could proceed safely, though slowly, to determine the whole sphere of pure reason completely and from general principles, in its circumference as well as in its contents. This was req This paper sets out to discuss the nature and relevance of Kant’s synthesis between sensibility and understanding, in relation to his introduction of the synthetic a priori judgment, in his Critique of Pure Reason.