being rendered impossible by tendinous resistance; yet I feel the peculiar impulse so acutely that, if I do not actually look at my hand, I am inclined to believe that my finger has moved. The impulse in question is the so-called "feeling of innervation," and we have to ask what is its nature.
The answer is, that it is nothing more nor less than the antecedent mental image of the movement to be executed. We constantly receive nerve-impulses by the sensory nerves which have their source in the skin, joints, tendons, and muscles; these impulses fuse into an aggregate sensation which informs us about the varying positions of our limbs. Like other sensations, this leaves behind it a mental image, and it is this mental image, brought up as the last result of the play of association, which immediately precedes the external movement and constitutes the "feeling of innervation."
Thus in external voluntary action as in voluntary thought, the ideal anticipation of a mental state precedes its actual realization. The two likewise agree in being accompanied by tensions in the muscles of the head. Our feeling of freedom in volition depends upon our consciousness that the effect perceived to be accomplished coincides with the ideal anticipation that preceded it. A voluntary act may thus be described as the perception, often accompanied by feelings of muscular tension, of an accomplished effect which was previously anticipated in idea.
Our analysis of volition thus discloses no elements which are not either sensations or reproductions of sensations; none, that is to say, not strictly co-ordinate with sensations like blue, hard, sour; and since sensations are readily conceivable as the passive concomitants of brain-events, it follows that the phenomena of volition are entirely compatible with the theory of parallelism.
In the introduction to his Contributions Dr. Münsterberg approaches the same question from a slightly different point of view. He inquires how those higher intellectual processes which Wundt groups together under the head of "apperception" are to be reconciled with the parallelism theory. It appears to be a fact that our ideas do not merely come and go of themselves, but that consciousness has the power to interpose and direct their movement, as a general directs the movements of troops, — joining, separating, and arranging them, holding back this and dismissing that, comparing one with another, selecting some from amongst the rest, and displaying now an increased, now a diminished activity. Now, while it is easy to conceive a physical basis for the sensational content of consciousness, it is difficult to conceive one for the activities of consciousness itself, and the question arises, how these are to be harmonized with the parallelism theory.
