THE BASIS OF SOCIAL SOLIDARITY 827
This genetic movement may be illustrated by the following diagram, in which the order and stages of actual group life are exhibited to the eye.
The expanding cone shows the widening of the factors con- cerned in the whole movement or progression : the instinctive or biological mode In passes into the plastic or psychological PI and this in turn is succeeded by the reflective or social proper So.
/«=Instinctive. Pfc=Pla8tic. 5'o:=Social. The spaces a, a, etc, show the increased area of facts and principles peculiar to each mode beyond those of the preceding.
In human society all these motives to solidarity exist together. We never leave our bodies behind, with their instinctive tend- encies, nor do we ever free ourselves from the compulsion of direct emotion and impulse, which tend to make us on occasion the plastic instruments of social suggestion. But still that which differentiates human society is the presence of reflective sociality.
V
In view of these facts, fully established, as I believe, in biology and psychology, certain more general points of interpretation may be suggested.
I. It will at once be seen that no strictly biological interpreta- tion can exhaust all the modes of collective life, with their ac- companying forms of solidarity. The biological form is one of physical heredity, it shows the regularity and compulsion of instinct. How can we account, on such principles, for the social transmission and the personal caprice of the plastic activities of
