Groundwork of the Metaphysics of Morals

In the Preface of Groundwork of the Metaphysics of Morals, Kant presents his plans for his book and explains why establishing a metaphysics of morals is necessary. While he acknowledges he will not be able to accomplish this task in one book, he hopes to lay the foundation for future work on the subject and prove “the identification and corroboration of the supreme principle of morality” (7, 4:392). Kant’s background in the sciences is evident here, as he lays out his plans for both the text and the development of philosophy as a field with methodical precision.

Kant explains he will borrow from three divisions of Ancient Greek sciences: physics, ethics, and logic. Laws of nature correspond to physics, principles of freedom are examined through ethics, and formal philosophy is ruled by logic. Philosophical ideas are classified as either “empirical” or “pure.” Empirical philosophy is guided by everyday human experience, and pure philosophy is defined by its capacity to utilize logic and a priori cognition. If a principle is grounded by a priori reasoning, it is understood through intuition alone and without any justification from personal experiences. Knowledge of these distinctions can help us understand what Kant means by metaphysics: pure philosophy directed toward a better understanding of the world around us.

Kant believes he can create a metaphysics of morals because physics and ethics rely on the “empirical part” of “practical anthropology” and the “rational part” of “moral science” (4, 4:389). In other words, we can use scientific techniques to understand ethical concepts. He also establishes the importance of his tasks by claiming we need a set universal framework to properly evaluate moral actions. Clarifying morality through metaphysics will make it easier for humans to evaluate their own actions through logic and reason.

Kant acknowledges that philosophy has attempted to tackle morality before but believes it has fallen short. He thinks that previous philosophers who grappled with this issue relied too much on empirical thought and human nature. Human experience is far too subjective and could not create a metaphysics of morals, which would need to be universal to succeed. In Kant’s opinion, moral laws under a metaphysics of morals should be understood through a priori cognition. Kant argues that we already view morals a priori, as we follow them for their own sake and commit to upholding moral obligations in our own lives. Moral laws justified by a priori cognition will leave no room for selfish interpretation, as it will be intuitively clear what they are and why they should be followed. He writes, “the ground of the obligation here must not be sought in the nature of the human being, or in the circumstances of the world in which he is placed, but a priori solely in concepts of pure reason, and that any other prescription that is founded on principles of mere experience [...] can indeed be called a practical rule, but never a moral law” (5, 4:389). Here, Kant expresses that while empirical thinking can justify the necessity of moral laws, it cannot be the groundwork of their formulation. We are used to applying morals to evaluate specific circumstances in our everyday lives. According to Kant’s logic, we should fit our actions to our understanding of morality instead of warping morality to understand our actions. Establishing a framework for morality that needs no outside justification is the key to ensuring people can adequately judge their intentions before acting in a way that may prove to be harmful.

Kant acknowledges he will not be able to provide a full proof for the metaphysics of morals in this text. However, he believes that by proving the existence of the supreme principle of morality, he is paving the way for future philosophers to finish this quest. While Groundwork is far from Kant’s only text on morality, he sees it as a key to improving the field of moral philosophy by providing a more accurate line of inquiry into defining moral actions.