This rook makes no claim to originality of thought, for its purpose is only to introduce beginners to what the great moralists have thought in the past and are thinking today about ethical matters. It differs from other elementary text-books in giving a larger place to the work of living writers on ethics, and to do so seems advisable even in an introductory text-book, because of the rich contributions made by twentieth-century moralists both to the interpretation of their predecessors and to original ethical speculation. Most teachers today feel that the older introductions, the best of which were written in the now unfamiliar language of late nineteenth century Idealism, are out of date, and the conviction that a more introduction in simple language is needed by undergraduates their first year's study of ethics has been my chief reason for writing this book. It is fitting that I should thank all those whose teachings and writings have been used in this book; the frequency with which the names of some moralists occur in the text or footnotes indicates those to whom I owe most. The arrangement of topics has been largely determined by their order in the syllabus for the first year's course in ethics, prescribed by the University of the Panjab, in which I have been privileged to be a teacher, and my own presentation of the subject has probably been influenced more than I realize by a long use of Mackenzie's Manual of Ethics, the text-book pre-scribed for that course. I am especially grateful to my wife who, after carefully reading my script, has pointed out many passages which in their original form were likely to be misunderstood by beginners, and has helped me to amend them, and to my sisters, Misses Isobel and Mary Lillie, who have undertaken the wearisome task of correcting proofs. In the third edition, I have added a chapter on 'The Language of Ethics'. which has occupied a large place in ethical discussions in the last few years. I wish to express my gratitude to my colleague, Dr R. W. Hepburn, of the Department of Moral Philosophy in this University, who read the chapter in manuscript, and made several most helpful suggestions.