excerpt from above site ;
" Kant's aim was to move beyond the traditional dichotomy between rationalism and empiricism. The rationalists had tried to show that we can understand the world by careful use of reason; this guarantees the indubitability of our knowledge but leaves serious questions about its practical content. The empiricists, on the other hand, had argued that all of our knowledge must be firmly grounded in experience; practical content is thus secured, but it turns out that we can be certain of very little. Both approaches have failed, Kant supposed, because both are premised on the same mistaken assumption.
Progress in philosophy, according to Kant, requires that we frame the epistemological problem in an entirely different way. The crucial question is not how we can bring ourselves to understand the world, but how the world comes to be understood by us. Instead of trying, by reason or experience, to make our concepts match the nature of objects, Kant held, we must allow the structure of our concepts shape our experience of objects. This is the purpose of Kant's Critique of Pure Reason (1781, 1787): to show how reason determines the conditions under which experience and knowledge are possible."