Page:Popular Science Monthly Volume 13.djvu/469

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VOLUNTARY MOTION.

But, again, a bright object is presented to a child. Its desire for it ultimates in a movement that misses it, and then in one that grasps it. In what respect do the mental accompaniments of the movement differ in the two cases? In nothing whatever. The mental phenomena which accompany both the failure and the success are a desire for the object and a volition for the movement. Next week or month, you hold the bright object before the child again, and he succeeds in grasping it every time; and still the mental accompaniments of the movement are the same—the same desire for the object, and the same volition for the movement—not for the wrong movement, even when the failure was made. Then, if the desire and the volition are precisely the same in both cases, why should one movement be a success and the other a failure? It is evident that the fact that the child has learned that he can make the movement does not contribute to the success, for the first success was made before he had learned that he could; and the knowledge that he can does not contribute to a future success, because it does not contribute in the least to a knowledge of how to do it. Then, where are we driven to? The mental accompaniments or phenomena do not (with a qualification which it is not important to explain here) contribute to the success of our voluntary movements. Therefore, we must look for the reason why one voluntary movement is a success and another a failure, in the phenomena of organization, and not in those of mind.

If the final conclusion above reached is true, there should be no difference, physiologically, between a voluntary and a reflex movement. And such we find to be the case. The essential physiological phenomena of a voluntary movement are, an impression upon a peripheral surface, conducted thence along certain nerves to a nervous centre which is thereby excited to a peculiar kind of molecular action, and that action generates what is called a nervous force, which is discharged through another set of nerves upon certain muscles, causing them to contract. The essential physiological phenomena of a reflex movement are precisely the same. The point of present interest in both, cases is that peculiar molecular action of the nervous centres (which, as we have stated, is essentially the same in both cases) which generates the nervous force that is discharged upon the muscles, causing their contraction. Now, if there is no essential difference, physiologically, between a voluntary and a reflex movement, in what do they differ? Of course, the former is the latter with volition superadded, or the latter is the former with volition deducted. And what is volition? Volition is simply a peculiar molecular action of a nervous centre of motion reflected upon consciousness—translated into a state of consciousness—symbolized in consciousness. The mental part of the phenomena—the volition—being simply a state of consciousness—a consciousness of the molecular action—then, the molecular action is a condition precedent to that state of consciousness which is a symbolical representation of it. The molecular action, being precedent to the symbol of itself, can-