6o4 THE AMERICAN JOURNAL OF SOCIOLOGY
are chiefly in feeling and emotional attitudes. Hence, we ordina- rily think of such relationships as husband and wife, parent and child, in terms of feeling. In larger social groups, however, built up chiefly upon the basis of acquired habits, common ideas and beliefs may be the chief expression of social co-ordination; but in any case, habitual modes of interaction must come to have attached to them certain feeling tones in the individuals concerned — that is, they must give rise to certain feeling attitudes of certain individuals toward each other. In animal groups, where the interactions are almost wholly instinctive, not much more than the feeling attitude may exist as the subjective accompaniment of social co-ordination, but in human societies, with their larger element of acquired habit, the chief subjective expressions of social co-ordination are frequently common ideas and beliefs; thus, in a modern nation, unity of action and of life is secured partly through sentiments like patriotism, but even more through certain generally accepted ideas and beliefs. Such generally accepted ideas and beliefs, which form the psychical basis of institutions, may be called "co-ordinating ideas." The import- ance of such co-ordinating ideas in human social and institutional life, although first emphasized by Comte, has not as yet been adequately investigated by sociologists.
The whole matter of uniformities of feeling, belief, and opin- ion in social groups evidently, then, must be studied in connection with social co-ordinations if it is to be understood; for the mental attitudes of individuals toward each other and toward their group as a whole are expressions of the way in which they are socially co-ordinated. These subjective expressions of social co- ordination are, of course, also marks of incipient stages of new forms of social organization as well as of existing forms ; for it is manifest that in a group of individuals carrying on a common life-process through interstimulation and response, mental atti- tudes mark the beginning of new co-ordinations, or common activities, as well as those co-ordinations that have become fixed as social habits.
Thus far in this discussion, our point of view has been that of the social habit, and it may be well to note a little more fully
