The Critique of Practical Reason is the second of Kant's three Critiques, one of his three major treatises on moral theory, and a seminal text in the history of moral philosophy. Originally published three years after his Groundwork to the Metaphysics of Morals, the Critique provides further elaboration of the basic themes of Kant's moral theory, gives the most complete statement of his highly original theory of freedom of the will, and develops his practical metaphysics. This new edition of Kant's Critique of Practical Reason – prepared by an acclaimed translator and scholar of Kant's practical philosophy – presents the first new translation of this work to appear for some years. A substantial and lucid introduction by Andrews Reath places the main themes of the Critique in the context of Kant's moral theory and his critical system.