Citations have been made from A. J. Ayer's Philosophical Essays and Edward Westermarck's Origin and Development of the Moral Ideas by permission of the Macmillan Co. of London; from C. D. Broad's Five Types of Ethical Theory by permission of Routledge and Kegan Paul; from Paul Edwards’ Logic of Moral Discourse by permission of the Free Press of Glencoe, Ill.; from A. C. Ewing's The Definition of Good by permission of the Macmillan Co. of New York; from R. M. Hare's The Language of Morals and W. D. Ross's The Right and the Good by permission of the Clarendon Press, Oxford; from R. B. Perry's General Theory of Value by permission of the Harvard University Press; from Perry's Thought and Character of William James by permission of Mr Bernard B. Perry; from B. Russell's History of Western Philosophy by permission of Simon & Schuster; from P. A. Schilpp's The Philosophy of John Dewey by permission of the Tudor Publishing Company; from C. L. Stevenson's Ethics and Language by permission of the Yale University Press; from H. Rashdall's Is Conscience an Emotion? by permission of Houghton Mifflin & Co. I acknowledge the courtesy of these publishers with thanks.