We may say, then, in a general manner, that none of the peripheral excitations that arrive at the sensorium in the form of a vibratory impression, of a living force in activity, remain there stationary, stored up in one place. They develop there a series of secondary reac tions, of energies regularly co-ordinated, which are inces santly distributed in the direction of the apparatuses of organic life, and represent the continuity of the primary movement, and, as it were, the modes of excretion of the living forces implanted in the organism, which here and there effect their physiological discharge.
Extrinsic Manifestations of Cerebral Processes. Genesis of the Will.—The processes of cerebral activity which reveal themselves externally, and make their exit from the organism in the form of voluntary conscious manifes tations, must be considered successively in the two prin cipal phases of their evolution : I. In their period of incubation, when the process of the will is still only constituted by a purely physical impression ; 2. In their second period of extrinsic manifestation, when they take form, reveal themselves in an apparent manner, and lay the purely motor regions of the nervous system under contribution.
t. In its preparatory phase of incubation, the process of the will is nothing but the riper and more advanced ultimate period of an anterior operation of the judg ment, constituted as we have already explained.
The human personality is seized upon by the arrival of the excitation emanating from the external world. It enters into participation and becomes associated with this ; and from this intricate connection results a true intra-cerebral automatic radiation, which produces the apparition of a series of agglomerated secondary ideas. But the matter does not stop here ; this inner personality having been thus seized upon, its sensibility having been touched in any manner whatever, has reacted by virtue of the vital forces that vibrate in it in a latent condition— it has been affected in the direction of its most profound affinities, and necessarily this reactionary period betrays itself by an unconscious desire for such or such a definite object, and by a repulsion from such or such another.
Desire, attraction, aversion, repulsion, are therefore new conditions of the sensorium which necessarily result in the natural course of things, and which thus become the primordial elements destined to constitute a process of voluntary activity.
2. The psychic operation which is to be resolved into an act of will is; then, in itself only the second bar of a movement already begun. It is only the regular expres sion of the human personality, seized on, and impressed by an old or recent excitation from the external world, and carrying back to the external world the different states of its sensibility in emotion, in the form of motor manifestations.
Hence, as a natural consequence, we come to the conclusion that the act of voluntary motion which is developed in the psychic regions, is nothing but a subordinate fact, a secondary phenomenon, the direct resultant of the shock of the sensibility in emotion and the spontaneous reaction of the sensorium. Motor power is then, physiologically, nothing but sensibility trans formed. The voluntary excitation comes to life in that subtle process in which the impressed human per sonality is aroused. From this reaction of the sen sibility it emerges as a natural consequence, like a vital force in evolution ; it is like an excito-motor process radiating from the sensitive regions of the spinal axis towards the anterior regions, which progresses motzt pro trio, develops, amplifies, perfects itself infallibly through the whole length of its journey, and expands in its last period into co-ordinated motor manifestations, the faith ful dependents of the sensitive excitations that have given it birth.