Kant's profound and challenging investigation into the nature of human reason is the central text of modern philosophy In his landmark work Kant argues that reason 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 of Pure Reason brings together 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.