Morality is often thought of as non-rational or sub-rational. In Moral Notions, first published in 1967, Julius Kovesi argues that the rationality of morality is built into the way we construct moral concepts. In showing this he also resolves the old Humean conundrum of the relation between 'facts' and 'values'. And he puts forward a method of reasoning that might make 'applied ethics' (at present largely a hodge-podge of opinions) into a constructive discipline. Kovesi's general theory of concepts - important in its own right - is indebted to his interpretation of Plato, and his three papers on Plato, first published here, explain this debt. This new edition of Moral Notions also includes a foreward by Philippa Foot, a biography of the author, and a substantial afterword in which the editors, Robert Ewin and Alan Tapper, explain the signficance of Kovesi's work.