Aggregation guarantees social intercourse, which is a mode of conflict. Conflict, according to Professor Giddings, becomes the basis of social growth.[XXII-39] Primary conflicts are those in which one adversary is completely outdone, and hence likely to be crushed, by the other. Secondary conflict refers to the contests between more or less evenly balanced forces. Primary conflict is conquest; secondary conflict is growth. Among people secondary conflict leads to the development of consciousness of kind through the successive steps of communication, imitation, toleration, co-operation, alliance. The supreme result is the production of pre-eminently social classes. Of these various factors, Professor Giddings particularly stresses imitation. “It is the factor of imitation in the conflict that gradually assimilates and harmonizes.”[XXII-40] Association reacts upon individuals and produces self-consciousness, which in turn creates social self-consciousness, or group awareness of itself. Social self-consciousness is characterized by rational discussion. With the rise of discussion, social memory, or traditions, becomes possible. Moreover, a sense of social values arises. Public opinion springs from the passing of judgment by the members of the group upon any matters of general interest.[XXII-41] Social memory, or traditions, becomes highly differentiated.[XXII-42] It consists of impressions concerning the tangible world, the intangible world, and the conceptional world. The traditions in any field, plus current opinion in that field, form the standards, ideals, faiths, “isms” of the time. For example, the integration of economic traditions with current economic opinions is the general standard of living of the time and place. The integration of the aesthetic tradition with current criticism is taste, and the modification of a traditional religious belief by current religious ideas is a faith. Inasmuch as consciousness of kind is the psychological basis of social phenomena, it is natural that the chief social value is the kind itself, or the type of conscious life that is characteristic of the society.[XXII-43] The social cohesion is another important social value. Social cohesion is vital to the unity of any group; therefore the group is usually willing to make many sacrifices in its own behalf. The distinctive possessions and properties of the community, such as territory, sacred or historic places, heroes, ceremonies, constitute the third class of social values. A fourth group is found in the general principles which promote the growth of the group; for example, the principles of liberty, equality, and fraternity. The social values largely determine the social choices of groups and the nature of social organizations.