15. Despite Sumner’s failure to appreciate the significance of a thoroughgoing psychological approach to an analysis of folkways, his description of these societal phenomena constitutes a unique and valuable contribution to social thought. Sumner’s rigorous attitude toward social life did not permit him to enter into an extensive interpretation of the folkways in the light of folk ideals. He dealt with what _is_ to the exclusion of what _ought to be_. He saw the past so clearly, and the present so much as a reflection of the past, that no enheartening forward look was possible. He rested his theories on the inexorable work of the laws of biological evolution, modified chiefly by his belief in a strong individualism. Sumner’s fundamental theses have been developed and modified by A. G. Kellor. Professor Kellor has projected the Darwinian principles of variation, selection, transmission, and adaptation into societal concepts. In fact, he has done this so well that he has given the Darwinian principles full sway, not allowing sufficiently for the rise and operation of complex psychic principles. He has made the folkways the connecting link between organic and societal evolution, but has not noted fully the new, countless, and often intangible but powerful factors by which societal evolution is characterized. 16. The rôle that concepts of conduct have played in the evolution of society, has been analyzed by E. A. Westermarck and L. T. Hobhouse. The former is usually known as an anthropologist, and the latter as a sociologist. Professor Westermarck has shown that, strictly speaking, a custom is not merely the habit of a certain group of people; it also involves a rule of conduct.[XVIII-21] It possesses two characteristics--habitualness and obligatoriness. Not every public habit, however, is a custom, involving an obligation.[XVIII-22] There may be certain practices which are more or less common in society, but which at the same time are generally condemned. The disapproval of these is as a rule not very deep or genuine. Dr. Westermarck has indicated that there is a close similarity between the conscience of a community and of an individual.[XVIII-23] If a group commits a sin twice, it is likely to be considered allowable. In order to get at the real nature of societal life, the “bad habits” as well as the professed opinions of groups must be examined. “Society” says Dr. Westermarck, “is the birthplace of the moral consciousness.”[XVIII-24] Emotions which are felt by the community at large tend to take the form of conduct standards. The moral emotions lead to a variety of moral concepts. These fall into two main classes: concepts of disapproval, such as the concepts, bad, vice, wrong; and concepts of approval, such as good, virtue, and merit.