The classic conceptions of moral theory are of remarkable importance in illuminating the obscure places of the moral life and in giving the student clues which will enable him to explore it for himself. But there is always danger of either dogmatism or a sense of unreality when students are introduced abruptly to the theoretical ideas. Instead of serving as tools for understanding the moral facts, the ideas are likely to become substitutes for the facts. When they are proffered ready-made, their theoretical acuteness and cleverness may be admired, but their practical soundness and applicability are suspected. The historical introduction permits the student to be present, as it were, at the social situations in which the intellectual instruments were forged. He appreciates their relevancy to the conditions which provoked them, and he is encouraged to try them on simple problems before attempting the complex problems of the present. By assisting in their gradual development he gains confidence in the ideas and in his power to use them. In the second part, devoted more specifically to the analysis and criticism of the leading conceptions of moral theory, the aim accordingly has not been to instill the notions of a school nor to inculcate a ready-made system, but to show the development of theories out of the problems and experience of every-day conduct, and to suggest how these theories may be fruitfully applied in practical exigencies. Aspects of the moral life have been so thoroughly examined that it is possible to present certain principles in the confidence that they will meet general acceptance. Rationalism and hedonism, for example, have contributed toward a scientific statement of the elements of conduct, even though they have failed as self-inclosed and final systems. After the discussions of Kant and Mill, Sidgwick and Green, Martineau and Spencer, it is possible to affirm that there is a place in the moral life for reason and a place for happiness,--a place for duty and a place for valuation. Theories are treated not as incompatible rival systems which must be accepted or rejected _en bloc_, but as more or less adequate methods of surveying the problems of conduct. This mode of approach facilitates the scientific estimation and determination of the part played by various factors in the complexity of moral life. The student is put in a position to judge the problems of conduct for himself. This emancipation and enlightenment of individual judgment is the chief aim of the theoretical portion.