In his Fundamental Principles of the Metaphysics of Morals Immanuel Kant outlined the structure of moral reasoning, but to reach this critical point in his philosophy he had to demonstrate how reasoning about ethics could emerge. While the Critique of Pure Reason offers the foundation for his theories of knowledge and reality and the manner in which we come to possess ideas about the world, Kant's Critique of Practical Reason shows how these mental processes are linked--how the mind moves from a formal understanding of reasoning in general to moral reasoning in...