Its 77 Academy pages make the Groundwork of the Metaphysics of Morals a short book, certainly by Kantian standards. Readers of the Critique of Pure Reason or the Metaphysics of Morals can easily get the impression – true or not – that they are looking at a ‘patchwork’ of previously existing material. The Groundwork is different. It was composed with great care. Moreover, Kant’s technical language is absent from the first section, whereas the second employs resounding concepts like that of human beings as ‘ends in themselves’ or that of a ‘kingdom of ends’ that we are morally bound to create through our actions. These qualities explain its enduring popularity.

At the same time, the Groundwork claims to be as revolutionary in the field of ethics as the Critique of Pure Reason was in theoretical philosophy. Kant argues that all other ethical theories are fundamentally unsound because they fail to separate the rational and the natural elements of human volition. An unconditional moral command – a ‘categorical imperative’ – can only be grounded in pure reason. But this revolution concerns the level of ethical theory, not that of morality. Kant claims to re-establish what he claims are the insights of an uncorrupted common understanding of value and duty against the dangerous perversions peddled by his philosophical opponents. He emphasizes the capacity for self-determination or ‘autonomy’ that is located within individual human beings; and yet, the law that we impose upon ourselves is not arbitrary, it commands with unrelenting necessity.

In his Groundwork of the Metaphysics of Morals, Immanuel Kant portrays the supreme moral principle as an unconditional imperative that applies to all of us because we freely choose to impose upon ourselves a law of pure practical reason. Morality is revealed to be a matter of autonomy. Today, this approach to ethical theory is as perplexing, controversial and inspiring as it was in 1785, when the Groundwork was first published. The essays in this volume, by international Kant scholars and moral philosophers, discuss Kant's philosophical development and his rejection of earlier moral theories, the role of happiness and inclination in the Groundwork, Kant's moral metaphysics and theory of value, and his attempt to justify the categorical imperative as a principle of freedom. They reflect the approach of several schools of interpretation and illustrate the lively diversity of Kantian ethics today.