Thus according to the philosophers before Kant, the law of contradiction, which asserts that nothing can at the same time have and not have a certain property, sufficed to establish the truth of all a priori knowledge.
Other German philosophers also joined in the enterprise of transforming Kant's critical philosophy into a metaphysical idealism—most notably, Hegel, Schelling, and Schopenhauer.
13-3Kant's critical philosophy and his Copernican revolution The turning point in Kant's intellectual development was his encounter with Hume's empiricism.
14-4-3Phenomenal and Noumenal Reality A major aspect of Kant's critical philosophy was his insistence that human knowledge is forever limited in its scope.