Immanuel Kant 
The Critique of Pure Reason 

The Critique of Pure Reason is a book by the German philosopher Immanuel Kant, in which the author seeks to determine the limits and scope of metaphysics. Also referred to as Kant’s 'First Critique’, it was followed by his Critique of Practical Reason and Critique of Judgment. Reason, Kant argues, is the seat of certain concepts that precede experience and make it possible, but we are not therefore entitled to draw conclusions about the natural world from these concepts. The Critique brings together the two opposing schools of philosophy: rationalism, which grounds all our knowledge in reason, and empiricism, which traces all our knowledge to experience. Kant’s transcendental idealism indicates a third way that goes far beyond these alternatives.