Groundwork of the Metaphysics of Morals (1785), also known as Grounding of the Metaphysics of Morals, is a work of modern philosophy by the philosopher Immanuel Kant. It is the first of his extensive writings on moral philosophy and attempts to establish a foundation for future works on moral theory. Kant believed that previous moral philosophers did not successfully define morality and argued that they based it too much on individual experiences. Groundwork of the Metaphysics of Morals seeks to prove that there is a supreme, universally held principle of morality that applies equally to all rational human beings. He expanded on this idea in his 1797 book, The Metaphysics of Morals, which applies some of Groundwork’s ideas in more specific contexts. Kant’s work in philosophy revolutionized how scholars approached ideas of reason, morality, and ethics.

This guide correlates to the edition published by Cambridge Texts in the History of Philosophy in 2018. It is the third printing of the revised edition.

Summary

Groundwork of the Metaphysics of Morals is composed of a preface and three sections. In the preface, Kant establishes his hopes for his writing. He acknowledges he will not be able to establish a complete metaphysics of morals at this time, but he believes he can prove the existence of a “supreme principle of morality” that governs all rational human beings. He asserts that all human beings can understand this principle intuitively, meaning it requires a priori cognition.

In the First Section, Transition from common to philosophical moral rational cognition, Kant argues that humans are uniquely fit to understand the principles of morality because of our capacity for reason. Kant establishes the importance of a “good will.” Anyone can have certain talents, but they will only benefit the world if the person gifted with them intends to use them for good. We can evaluate a person’s intentions by focusing on their desired outcome, or end. Furthermore, we can pursue good will by following duty. Kant offers three propositions about duty: the first tells us to identify an individual’s reason for following duty, the second asks that we evaluate their motivations (their maxim), and the third states that a truly good maxim can be applied as a universal law. This good maxim stems from an understanding of our obligation to obey universal moral laws.

In the Second Section, Transition from popular moral philosophy to the metaphysics of morals, Kant argues that morality is governed by laws. These laws are called imperatives. Hypothetical imperatives tell us how to act in pursuit of a specific outcome, whereas categorical imperatives are ends in themselves. Categorical imperatives govern morality. Kant uses the categorical imperative to expand his previous assertion about evaluating maxims, writing that the only categorical imperative is to act as though your maxim is a universal moral law. These universal laws cannot contradict themselves—for example, we can never legitimize suicide because taking life contradicts the fundamental principle of nature. As such, the categorical imperative acts as a foundation for all imperatives related to duty. In an ideal world, where all humans adhere to the categorical imperative, we enter the kingdom of ends. The kingdom of ends is a complete moral community that is composed of rational beings with self-legislating wills who treat each other as ends in themselves. If a will is self-legislating, it is autonomous.

In the Third Section, Transition from the metaphysics of morals to the critique of pure practical reason, Kant argues that freedom is a key component of the rational will. He wants to explain the connection between freedom and morality and demonstrate why someone would choose to subject themselves to the categorical imperative and join the kingdom of ends. Kant concedes that certain ideas of morality can be circular since it seems as though we require morality to experience free will, but morality requires willfully subjecting ourselves to stringent laws. The key to separating the two concepts is to split the world into what is governed by “appearances” and “things in themselves.” This distinction leads all rational beings to understand we are bound by natural laws (including morality) that have a foundation in the realm of reason. He then explains that rational beings know they are free through reason, and it allows us to participate in an intelligible world that allows our actions to conform with free will. Here, we could not help but act morally. The alternative, which is living in a sensible world, would still be moral because we can still understand that we ought to be moral. While this does not conclusively prove the existence of intrinsic human freedom, it does demonstrate that freedom and morality are connected by reason.