The main difference between the self-regarding sentiment and the developed group sentiment is that the latter commonly involves an element of devotion to the group for its own sake and the sake of one’s fellow members. That is to say, the group sentiment is a synthesis of the self-regarding and the altruistic tendencies in which they are harmonised to mutual support and re-enforcement: the powerful egoistic impulses being sublimated to higher ends than the promotion of the self’s welfare[41]. Further, the group has, or may have, a greater continuity of existence than the individual, both in the past and in the future; and for this reason, and because also it includes the purely altruistic tendency, the group sentiment is capable of idealisation in a high degree and of yielding satisfactions far more enduring and profound than the most refined self-sentiment. Both knowledge of the group and the growth of the group sentiment are greatly promoted by two processes, in the absence of which the group spirit can attain only a very modest development. These are free intercourse within the group and free intercourse between the group and other groups. We shall have occasion to discuss and illustrate them in later chapters. CHAPTER V PECULIARITIES OF GROUPS OF VARIOUS TYPES We have discussed the psychology of the simple crowd or unorganised group; and taking an army as an extreme and relatively simple type of the highly organised group, we have used it to illustrate the principal ways in which organisation of the group modifies its collective life, raising it in many respects high above that of the crowd. I propose now to discuss very briefly the peculiarities of groups of several types. Some classification of groups seems desirable as an aid to the discovery of the general principles of collective life and their application to the understanding of social life in general. It seems impossible to discover any single principle of classification. Almost every group that enjoys a greater continuity of existence than the simple crowd partakes in some degree of qualities common to all. But we may distinguish the most important qualities and roughly classify groups according to the degrees in which they exhibit them. Apart from crowds, which, as we have seen, may be either fortuitously gathered or brought together by some common purpose, there are many simple groups which, though accidental in origin (i.e. not brought together by common purpose or interest) and remaining unorganised, yet present in simple and rudimentary form some of the features of group life.