cal phenomena into mental phenomena, the latter alternative would seem the more acceptable of the two.[1]
Nevertheless there is of course an evolution of mind; a development of modes of response from simple to compound to complex, from reflex to tropism to instinct, through memory and imagination to intellect and reason. To the reader who can pass alive through these 1400 pages of physiological and psychological analysis there will come an overwhelming sense of the continuity of life and the continuity of mind; he will see, as on a retarded cinematograph, the formation of nerves, the development of adaptive reflexes and instincts, and the production of consciousness and thought through the clash of conflicting impulses. "Intelligence has neither distinct grades nor is it constituted by faculties that are truly independent, but its highest manifestations are the effects of a complication that has arisen by insensible steps out of the simplest elements."[2] There is no hiatus between instinct and reason; each is an adjustment of inner relations to outer relations, and the only difference is one of degree, in so far as the relations responded to by instinct are comparatively stereotyped and simple, while those met by reason are comparatively novel and complex. A rational action is simply an instinctive response which has survived in a struggle with other instinctive responses aroused by a situation; "deliberation" is merely the internecine strife of rival impulses.[3] At bottom, reason and instinct, mind and life, are one.
Will is an abstract term which we give to the sum of our active impulses, and a volition is the natural flow of an unimpeded idea into action.[4] An idea is the first stage of an action, an action is the last stage of an idea. Similarly, an emotion is the first stage of an instinctive action, and the expression of the emotion is a useful prelude to the completed
