Note 220 — LECTURE XV INSTINCTS, SENTIMENTS, AND CONFLICTS

... “Every instinctive process has the three aspects of all mental processes, the cognitive, the affective, and the conative. Now, the innate psychophysical disposition, which is an instinct, may be regarded as consisting of three corresponding parts, an afferent, a central, and a motor or efferent part, whose activities are the cognitive, the affective, and the conative features respectively of the total instinctive process. The afferent or receptive part of the total disposition is some organized group of nervous elements or neurones that is specially adapted to receive and to elaborate the impulses initiated in the sense-organ by the native object of the instinct; its constitution and activities determine the sensory content of the psychophysical process. From the afferent part the excitement spreads over to the central part of the disposition; the constitution of this part determines in the main the distribution of the nervous impulses, especially the impulses that descend to modify the working of the visceral organs, the heart, lungs, blood vessels, glands, etc., in the manner required for the most effective excitation of the instinctive action; the nervous activities of this central part are the correlates of the affective or emotional aspect or feature of the total physical process. The excitement of the efferent or motor part reaches it by the way of the central part; its construction determines the distribution of impulses to the muscles of the skeletal system by which the instinctive action is effected, and its nervous activities are the correlates of the conative element of the physical process, of the felt impulse to action.” William McDougall. An introduction to Social Psychology, p. 32.