The experience only can generate the cause notion and Hume concludes, then, that the reason does not possess facultieses to think cause relations. The criticism of Kant is, then, the synthesis of two basic chains of the knowledge: the dogmtico rationalism and the skeptical empirismo. Beyond awaking Kant of dogmtico sleep, the skepticism of Hume granted to the philosophical inquiries of Kant a total diverse orientation, making with that it inquired on the knowledge, while its conditions and limits. In this manner, Kant differentiates philosophy and sciences, affirming that the proper object of each one is diverse. The philosophy has as object the knowledge, what it takes the criticism to conclude that the knowledge is resulted of a synthesis of sensitivity and the agreement.

The criticista theory of Kant is unfolded in the trilogy of the Critical one of the pure reason, of the Critical one of the practical reason and the Critical one of the judgment college. Kant in such a way perceived the importance of the questions raised for the empiristas how much the raised ones for the racionalistas. With this, he finished elaborating the overcoming between two chains. But, he is significant that Kant, inserted in the context of the German rationalism, has dedicated its Critical one of pure reason the Bacon, the starter of the empirismo. This workmanship demanded twelve years of meditation, being concluded in the year of 1781. It does not present only one point of bending in the workmanship of our philosopher, but it was, also, a great change produced in the modern philosophy.

We can say that its main objective is the inquiry of the possibility of metaphysics to be considered a science in the limits of the reason human being. With this, metaphysics becomes an object of critical inquiry of the reason. The workmanship presented after years of intense work, cannot be considered a metaphysics to the molds of the system of Leibniz or Wolff, but a propedutica science that would precede, according to Kant, to its proper metaphysics.