section_path: Philosophy/Moral thought
section_name: Moral thought
paragraph_text: Moral thought
  
  Kant developed his ethics, or moral philosophy, in three works: Groundwork of the Metaphysics of Morals (1785), Critique of Practical Reason (1788), and Metaphysics of Morals (1797).With regard to morality, Kant argued that the source of the good lies not in anything outside the human subject, either in nature or given by God, but rather is only the good will itself. A good will is one that acts from duty in accordance with the universal moral law that the autonomous human being freely gives itself. This law obliges one to treat humanity — understood as rational agency, and represented through oneself as well as others — as an end in itself rather than (merely) as means to other ends the individual might hold. Kant is known for his theory that all moral obligation is grounded in what he calls the " categorical imperative ", which is derived from the concept of duty. He argues that the moral law is a principle of reason itself, not based on contingent facts about the world, such as what would make us happy; to act on the moral law has no other motive than "worthiness to be happy".