The Critique of Pure Reason, published in 1781, by German philosopher Immanuel Kant, cornerstone of modern philosophy, is one of the most important works on metaphysics ever published and is often seen as the culmination of centuries of early-modern philosophical thought. The Critique of Pure Reason, also known as The First Critique, incorporates in-depth discussions on empirical reason, "pure" reason, human knowledge as a whole, space and time, cause and effect, and much, much more.