Kant's Moral Philosophy

Just as the first Critique set out critically the synthetic a priori principles of theoretical reason, the Groundwork of the Metaphysic of Morals (1785) set out critically the synthetic a priori principles of practical reason. This is a brief and eloquent presentation of Kant's moral system.  In morals, Kant's starting point is that the only thing which is good without qualification is a good will. Talents, character, self-control, and fortune can be used to bad ends; even happiness can be corrupting. It is not what it achieves that constitutes the goodness of a good will; good will is good in itself alone.  Even if, by some special disfavour of destiny, or by the niggardly endowment of stepmotherly nature, this will is entirely lacking in power to carry out its intentions; if by its utmost effort it still accomplishes nothing, and only good will is left ... ; even then it would still shine like a jewel for its own sake as something which has its full value in itself.