This is not a general introduction to Kant’s ethics; it is not primarily concerned with expounding the Groundwork, the Analytic of the Critique of Practical Reason or the Metaphysic of Morals; excellent commentaries now exist on all those central ethical works. I have written for the reader or student who has some knowledge of Kant’s ethical doctrine, as it can be found in one or more of the texts mentioned, but who has not the time to read all those other works in Kant’s voluminous output which are relevant to and often of great importance for his view of ethics. My aim is to put the well-known doctrines in the overall context of Kant’s developing philosophy. And I am concerned, not so much with the ethical doctrines themselves, as with Kant’s view of the nature of morality—what he took morality to be—as it developed throughout his life. If to put something in context is to understand it better, then such a programme will help in attaining a general view of Kant’s concerns in ethics; and it may well hold some surprises for those whose Kantian diet has been confined, say, to the Groundwork.

I think it is true to say that general verdicts on Kant’s ethics are still common which such a fuller view shows to be quite inaccurate—for instance, that he was not concerned with ends of action, or that the postulates of practical reason are irrelevant additions to his central doctrines, or that he is the stern prophet of ‘duty for duty’s sake’, without regard to considerations of human fulfilment or happiness. Such mistaken views are less common in Britain now than they used to be; but there is still widespread lack of knowledge of many of Kant’s writings which are important for his ethical views, such as the Dreams of a Spirit-Seer and the essays on history. This book deals with most of Kant’s published writings, in so far as they are relevant to ethics, and so it provides a general view of the origins, development and metaphysical context of his ethical theory.

It is probable that many readers will wish to study what I have to say on specific topics in Kant, without having to consider material which is of secondary importance for their purposes. Consequently, I have divided the text into numbered sections with appropriate headings, and have included an analytical table of contents in which the various main topics are listed.

Finally, it should be noted that I have consistently used the word ‘metaphysics’ in a non-Kantian sense—i.e. to mean, not a priori elements of knowledge, but a general speculative account of the nature of reality, derived from whatever source. I have found it convenient to use the word in this sense; and, as long as it is remembered that it is a non-Kantian sense, it should cause no confusion.

I should like to thank the editor of the Philosophical Quarterly for permission to use material from ‘Kant’s Teleological Ethics’ (1971). I am also grateful to Leslie Stevenson and those who read the manuscript for my publishers, who made very helpful comments.