To get a good idea of how the moral world revealed itself to a Father of the Church in the fifth century, we have only to turn to that most fascinating of autobiographies, the _Confessions_ of St. Augustine. His _City of God_ is too long, though interesting. Augustine's thought influenced the world for centuries. Then we may take a long jump and come down to St. Thomas, the great Scholastic of the thirteenth century. To get acquainted with him, we may turn to the English versions by Rickaby, _Aquinas Ethicus_. Those of us who are smugly satisfied at belonging to the twentieth century must remind ourselves that there were great men in the thirteenth, and that many among our contemporaries are still listening to them. We Protestant teachers of philosophy are sometimes in danger of forgetting this. A strictly fresh century and a strictly fresh egg cannot claim to be precisely on a par. I do not think that I shall add the modern moralists to this list. There are a great many of them, and many of them are very good. But they are discussed at length in Part VII, which deals with the schools of the moralists. Citations and references are there given. I think, however, that I ought to add here that I should regard an ethical collection incomplete that did not include at least one of the comprehensive works on morals lately offered us by certain sociologists. Westermarck's wonderful book--a mine of information--on _The Origin and Development of the Moral Ideas_, or the admirable book by Hobhouse, _Morals in Evolution_, will serve to fill the gap. Information regarding editions of all the books I have mentioned can be had in most public libraries, or from any good publisher and book-seller. As for the reading to accompany these Chapters, I-III, I suggest looking over the chapters by Westermarck and Hobhouse, indicated in foot-notes. He who would realize how men have differed in their moral outlook on life might read the lives of Aristippus, Epicurus and Zeno, in Diogenes Laertius; or follow the account, in Sidgwick's _History of Ethics_, of Aristotle's teaching, as compared with the ethics of the Church. 2. Chapters IV to VII.--These chapters on ethics as science and on ethical method do not appear to me to call for extensive notes. Several foot-notes are given which might be followed up. I think it would be a very good thing for the student to read chapters i and vi in Sidgwick's admirable work, The _Methods of Ethics_.