I believe, therefore, that suggestion as an active agent should be the object of the most attentive study for the historians and the sociologists. Where this factor is not reckoned with, a whole series of historical and social phenomena is threatened with the danger of incomplete, insufficient, and perhaps even incorrect elucidation.
III. INVESTIGATIONS AND PROBLEMS
1. The Process of Interaction
The concept of universal interaction was first formulated in philosophy. Kant listed community or reciprocity among his dynamic categories. In the Herbartian theory of a world of coexisting individuals, the notion of reciprocal action was central. The distinctive contribution of Lotze was his recognition that interaction of the parts implies the unity of the whole since external action implies internal changes in the interacting objects. Ormond in his book The Foundations of Knowledge completes this philosophical conception by embodying in it a conclusion based on social psychology. Just as society is constituted by interacting persons whose innermost nature, as a result of interaction, is internal to each, so the universe is constituted by the totality of interacting units internally predisposed to interaction as elements and products of the process.
In sociology, Gumplowicz arrived at the notions of a "natural social process" and of "reciprocal action of heterogeneous elements" in his study of the conflict of races. Ratzenhofer, Simmel, and Small place the social process and socialization central in their systems of sociology. Cooley's recent book The Social Process is an intimate and sympathetic exposition of "interaction" and the "social process." "Society is a complex of forms or processes each of which is living and growing by interaction with the others, the whole being so unified that what takes place in one part affects all the rest. It is a vast tissue of reciprocal activity, differentiated into innumerable systems, some of them quite distinct, others not readily traceable, and all interwoven to such a degree that you see different systems according to the point of view you take."[154]
This brief résumé of the general literature upon the social process and social interaction is introductory to an examination of the more concrete material upon communication, imitation, and suggestion.
2. Communication
"Many works have been written on Expression, but a greater number on Physiognomy" wrote Charles Darwin in 1872. Physiognomy, or the interpretation of character through the observation of the features, has long been relegated by the scientific world to the limbo occupied by astrology, alchemy, phrenology, and the practice of charlatans.
While positive contributions to an appreciation of human expression were made before Darwin, as by Sir Charles Bell, Pierre Gratiolet, and Dr. Piderit, his volume on The Expression of the Emotions in Man and Animals marked an epoch in the thinking upon the subject. Although his three principles of utility, antithesis, and direct nervous discharge to explain the signs of emotions may be open to question, as the physiological psychologist, Wilhelm Wundt, asserts, the great value of his contribution is generally conceded. His convincing demonstration of the universal similarity of emotional expression in the various human races, a similarity based on a common human inheritance, prepared the way for further study.
Darwin assumed that the emotion was a mental state which preceded and caused its expression. According to the findings of later observation, popularly known as the James-Lange Theory, the emotion is the mental sign of a behavior change whose external aspects constitute the so-called "expression." The important point brought out by this new view of the emotion was an emphasis upon the nature of physiological changes involved in emotional response. Certain stimuli affect visceral processes and thereby modify the perception of external objects.