One of the important documents in the history of modern psychology, particularly for the psychology of language, is Darwin's Expression of the Emotions in Man and Animals. Here Darwin carried over his theory of evolution into the field of what we call »conscious experience«. What Darwin did was to show that there was a whole series of acts or beginnings of acts which called out certain responses that do express emotions. If one animal attacks another, or is on the point of attacking, or of taking the bone of another dog, that action calls out violent responses which express the anger of the second dog. There we have a set of attitudes which express the emotional attitude of dogs; and we can carry this analysis into the human expression of emotion.
The part of our organism that most vividly and readily expresses the emotions is the face, and Darwin studied the face from this point of view. He took, naturally, the actor, the man whose business it is to express the emotions by the movements of the countenance, and studied the muscles themselves; and in studying them he undertook to show what the value of these changes of the face might be in the actual act. We speak of such expressions as those of anger, and note the way in which the blood may suffuse the face at one stage and then leave it at another. Darwin studied the blood flow in fear and in terror. In these emotions one can find changes taking place in the blood flow itself. These changes have their value. They represent, of course, changes in the circulation of blood in the acts. These actions are generally actions which are rapid and can only take place if the blood is flowing rapidly. There must be a change in the rhythm of circulation and this generally registers itself in the countenance.
Many of our acts of hostility exhibit themselves in attitudes of the face similar to animals which attack with their teeth. The attitude, or in a more generalized term, the gesture, has been preserved after the value of the act has disappeared. The title of Darwin's work indicates his point of approach. He was dealing with these gestures, these attitudes, as expressive of emotions and assuming at the time that the gesture has this function of expressing the emotions. That attitude has been preserved, on this view, after the value of the act has disappeared. This gesture seems to remain for the purpose of expressing emotions. One naturally assumed there an attitude in the experience of animals which answers in some sense to those of the human animal. One could apply the doctrine of the survival of the fittest here also. The implication in this particular case was that these gestures or attitudes had lost the value which they had in the original acts, and yet had survived. The indication was that they had survived because they served certain valuable functions, and the suggestion was that this was the expression of the emotions. That attitude on Darwin's part is reflected in the work of other psychologists, men who were interested, as Darwin was, in the study of the act, in the information that is conveyed by one individual to another by his attitude. They assume that these acts had a reason for existence because they expressed something in the mind of the individual. It is an approach like that of the philologist. They assume that language existed for the purpose of conveying certain ideas, certain feelings.
If one considers, he realizes that this is a false approach. It is quite impossible to assume that animals do undertake to express their emotions. They certainly do not undertake to express them for the benefit of other animals. The most that can be said is that the »expressions« did set free a certain emotion in the individual, an escape valve, so to speak, an emotional attitude which the animal needed, in some sense, to get rid of. They certainly could not exist in these lower animals as means of expressing emotions; we cannot approach them from the point of view of expressing a content in the mind of the individual. We can, of course, see how, for the actor, they may become definitely a language. An actor, for example, may undertake to express his rage, and he may do it by an expression of the countenance, and so convey to the audience the emotion he intended. However, he is not expressing his own emotion but simply conveying to the audience the evidence of anger, and if he is successful he may do it more effectively, as far as the audience is concerned, than a person who is in reality angered. There we have these gestures serving the purpose of expression of the emotions, but we cannot conceive that they arose as such a language in order to express emotion. Language, then, has to be studied from the point of view of the gestural type of conduct within which it existed without being as such a definite language. And we have to see how the communicative function could have arisen out of that prior sort of conduct.
The psychology of Darwin assumed that emotion was a psychological state, a state of consciousness, and that this state could not itself be formulated in terms of the attitude or the behavior of the form. It was assumed that the emotion is there and that certain movements might give evidence of it. The evidence would be received and acted upon by other forms that were fashioned like itself. That is, it presupposed the conscious state over against the biological organism. The conscious state was that which was to be expressed in the gesture or the attitude. It was to be expressed in behavior and to be recognized in some fashion as existent in the consciousness of the other form through this medium of expression. Such was the general psychological attitude which Darwin accepted.
Contrary to Darwin, however, we find no evidence for the prior existence of consciousness as something which brings about behavior on the part of one organism that is of such a sort as to call forth an adjustive response on the part of another organism, without itself being dependent on such behavior. We are rather forced to conclude that consciousness is an emergent from such behavior; that so far from being a precondition of the social act, the social act is the precondition of it. The mechanism of the social act can be traced out without introducing into it the conception of consciousness as a separable element within that act; hence the social act, in its more elementary stages or forms, is possible without, or apart from, some form of consciousness.
4. RISE OF PARALLELISM IN PSYCHOLOGY
The psychology which stresses parallelism has to be distinguished from the psychology which regards certain states of consciousness as existing in the mind of the individual, and succeeding each other in accordance with their own laws of association. The whole doctrine of the psychology which follows Hume was predominantly associationistic. Given certain states of consciousness they were supposed to be held together by other similar elements. Among these elements were those of pleasure and pain. Connected with this atomism of associated conscious states was a psychology of action grounded on the association of pleasure and pain with certain other sensations and experiences. The doctrine of association was the dominant psychological doctrine; it dealt with static rather than dynamic experience.
The pushing of the psychological side further and further into the central nervous system revealed that there were whole series of experiences which might be called sensations and yet were very different from those which could be regarded as static, such as sound, odor, taste, and color. Association belonged to this static world. It was increasingly recognized that there was a large part of our experience which was dynamic. The form of actual doing was present in some of the sensations which answered to the innervation of sensory nerves. There was also the study of those tracts which went down to the viscera, and these certainly were aligned with the emotional experiences. The whole process of the circulation of the blood had been opened up, and the action which involved the sudden change of the circulation of the blood. Fear, hostility, anger, which called for sudden movement, or terror, which deprived the individual of the ability to move, reflected themselves in the visceral conditions; and also had their sensory aspects connected with the central nervous system. There was, then, a type of experience which did not fall into place in a static world. Wilhelm Wundt approached his problem from the standpoint of this sort of physiology which offered a clew by means of which one could follow out these various dynamic experiences into the mechanism of the organism itself.
The treatment which had been given to the central nervous system and its motor and sensory nerves had been that of bringing a nerve current to a central nervous system which was then in turn responsible for a sensation that happened in »consciousness«. To get a complete statement of what we call the act one had to follow up the sensory side and then follow out the motor results that took place because of what happened in consciousness. The physiology to which I have referred in a certain sense separated itself from the