Summary

Immanuel Kant's "Groundwork of the Metaphysics of Morals" is a foundational text in moral philosophy, aiming to establish the supreme principle of morality. Kant seeks to uncover this principle through a method that moves from common moral cognition to its philosophical determination and back again, ensuring its applicability and grounding in human understanding.

The book begins by exploring the concept of a 'good will,' which Kant posits as the only thing that is good without limitation. He contrasts actions done from duty with those done from inclination, arguing that only actions performed out of duty possess true moral worth. Kant introduces the idea of a 'categorical imperative,' a command of reason that is unconditional and applies to all rational beings, setting it apart from hypothetical imperatives that depend on specific desires or goals.

Kant formulates the categorical imperative in several ways, most notably as the 'Formula of Universal Law,' which dictates that one should act only according to a maxim that one could will to become a universal law. He illustrates this with examples such as the wrongness of making false promises and the importance of developing one's talents. The text also introduces the 'Formula of Humanity,' emphasizing that rational beings should always be treated as ends in themselves and never merely as means. This leads to a vision of an ideal human community or 'kingdom of ends,' where individuals respect each other's autonomy and reason.

The "Groundwork" delves into the concept of autonomy, asserting that moral laws must be self-imposed by rational beings rather than derived from external authority or empirical conditions. Kant explores the relationship between freedom and morality, arguing that a free will is essentially one that operates under moral laws. He grapples with the apparent contradiction between human freedom and the determinism of the natural world by proposing that humans exist in both a 'world of sense' and a 'world of understanding.' As members of the latter, we are autonomous and governed by reason, which enables morality to have authority over our wills.

Kant acknowledges the limits of human reason in fully explaining how pure reason can be practical or how freedom is possible. He suggests that moral interest stems from the ideal of a universal kingdom of ends, where rational beings act according to maxims of freedom as if they were laws of nature. This text, while setting foundational principles, recognizes the inherent difficulties in fully comprehending the basis and implementation of these moral concepts, marking the boundary of what practical philosophy can achieve.