=Theory and Practice.=--Finally, if we can discover ethical principles these ought to give some guidance for the unsolved problems of life which continually present themselves for decision. Whatever may be true for other sciences it would seem that ethics at least ought to have some practical value. "In this theater of man's life it is reserved for God and the angels to be lookers on." Man must act; and he must act well or ill, rightly or wrongly. If he has reflected, has considered his conduct in the light of the general principles of human order and progress, he ought to be able to act more intelligently and freely, to achieve the satisfaction that always attends on scientific as compared with uncritical or rule-of-thumb practice. Socrates gave the classic statement for the study of conduct when he said, "A life unexamined, uncriticized, is not worthy of man." § 2. CRITERION OF THE MORAL It is not proposed to attempt at this point an accurate or minute statement of what is implied in moral conduct, as this is the task of Part II. But for the purposes of tracing in Part I. the beginnings of morality, it is desirable to have a sort of rough chart to indicate to the student what to look for in the earlier stages of his exploration, and to enable him to keep his bearings on the way. Certain of the characteristics of the moral may be seen in a cross-section, a statement of the elements in moral conduct at a given time. Other characteristics come out more clearly by comparing later with earlier stages. We give first a cross-section.