Immanuel Kant (1724-1804) was one of the most influential philosophers of all time. His profound thoughts on aesthetics, ethics, and knowledge has had an enormous impact on all subsequent philosophy. Kant asked questions like “What is morally permissible, and what is morally obligatory?” and explored the answers in Fundamental Principles of the Metaphysics of Morals. Kant's idea of the categorical imperative is a logical proof of the golden rule and the centerpiece of this work. It is his most famous contribution to ethical discussion, and knowledge of his reasoning in this book is essential to students of history, philosophy, and religion.