A Theory of Emotions from the Physiological Standpoint
Prof. Dewey having shown that it is possible to make a complete teleological statement of the emotions along the line of the discharge theory, it is interesting to see how far such a statement may be paralleled by a physiological theory.
(163) This would involve, also, a physiological theory of pleasure and pain. As pain can be differentiated from the sensations in connection with which it generally appears in consciousness, as it shows itself under circumstances in which the tissue of the end organs or the nerves themselves are affected, and as in the diseases in which we find pain as a constant concomitant, those parts are affected, which are richly supplied with blood vessels by means of supporting and nourishing tissues (Rindfleisch's intermediarer Ernahrunsapparat), and as in those diseases which pass usually without pain (as in the catarrhs of the various mucous membranes) the tissues affected are poorly supplied with such blood vessels, and enter into relation with the capillaries generally through the lymph, for the purposes of secretion, it becomes at least probable that, physiologically, pain may be considered as the interference through poisons or violence or otherwise with the process of nutrition as carried out in the finer arteries and blood vessels. Pleasure must from this standpoint be considered as physiologically the normal or rather hightened[sic] process of nutrition in the organs, and the nerve paths which connect these with the central nervous system would be probably the sympathetic.
In the simple instinctive act that lies behind every emotion, the vaso-motor system is called into action by the enlargement of the small blood vessels in the muscles and sweat glands. To maintain the blood pressure the finer blood vessels in the abdominal tracts are closed by the constrictors of that region, and the action of the heart may also be increased by the accelerators. The vaso-motor system thus is, in these simpler instinctive acts, in automatic connection with the senso-motor. The act must commence before the flow of blood can take place. It is in connection with this increased flow of blood that we have to assume the emotional tones of consciousness arise according to the discharge theory. Within the act it would answer only to interest. It is in the preparation for action that we find the qualitatively different emotional tones, and here we find increased flow of blood before the act. We find also what we may term symbolic stimuli, which tend to arouse
(164) the vaso-motor processes that are originally called out only by the instinctive acts. These stimuli in the form in which we can study them, seem to be more or less rhythmical repetitions of those moments in the act itself which call forth especially the vaso-motor response. In this form they are recognized as aesthetic stimuli, and may be best studied in the war and love dances. It is under the influence of stimuli of this general character that the emotional states and their physiological parallels arise. The teleology of these states is that of giving the organism an evaluation of the act before the coördination that leads to the particular reaction has been completed.