(3) And since, as we have seen, the significance, either of the individual conscience, or of the social conscience revealed in custom, law and public opinion, can hardly become apparent to one who does not bring within his horizon many consciences individual and social, he should enlarge his view so as to include such. The moralists, in our day, show an increasing tendency to pay serious attention to this mass of materials. They do not confine their attention to the moral standard which this man or that has accepted as authoritative for him, nor to that accepted as authoritative in a given community. They study _man_-- man in all stages of his development and in material and social settings the most diverse. (4) Nor should the student of ethics overlook the work which has been done by those moralists who have gone before him. He who has studied descriptive anatomy is aware of the immense service which has been done him by the unwearied observations of his predecessors; observations which have been put on record, and which draw his attention to numberless details of structure that would, without such aid, certainly escape his attention. Ethics is an ancient discipline. It has fixed the attention of acute minds for many centuries. He who approaches the subject naively, without an acquaintance with the many ethical theories which have been advanced and the acute criticisms to which they have been subjected, will almost certainly say what someone has said before, and said, perhaps, much better. The valor of ignorance will involve him in ignominious defeat. (5) It is evident that the moralist must make use of materials offered him by workers in many other fields of science. The biologist may have valuable suggestions to make touching the impulses and instincts of man. The psychologist treats of the same, and exhibits the work of the intellect in ordering and organizing the impulses. He studies the phenomena of desire, will, habit, the formation of character. The anthropologist and the sociologist are concerned with the codes of communities and with the laws of social development. The fields of economics, politics and comparative jurisprudence obviously march with that cultivated by the student of ethics. 18. THE PHILOSOPHER AS MORALIST.--In all these sciences at once it is not possible for the moralist to be an adept. The mass of the material they furnish is so vast that the ethical writer who starts out to master it in all its details may well dread that he may be overcome by senility before he is ready to undertake the formulation of an ethical theory. It does not follow, however, that he should leave to those who occupy themselves professionally with any of these fields the task of framing a theory of morals. He must have sufficient information to be able to select with intelligence what has some important bearing upon the problem of conduct, but there are many details into which he need not go. It is well to note the following points: