it, and offering the ideational centre D the opportunity to assume the function of motivating the will in terms of a final as well as an efficient cause, — not having reckoned with this conception of the case, he neither realizes the possibility of freedom nor understands the nature and relation of intelligence, or of ideational motives, to volition.
Now if we return to the exposition of Figure 2 we shall understand the question more clearly. In the first place, the lowest form of activity is that of the reflex arc, BAC, in which action is purely the result of stimulus and motor reaction, and in which there is no accompaniment of consciousness. There is in this case neither freedom nor the proof of it: there is no freedom because the action is under the sole determination of external influences; and there is no proof of it because there is no interruption of the transition from the first to the last term of the series, which would throw the causal energy upon something outside the series. This kind of action is peculiar to organic life of the insensible order and to that portion of all higher organisms which represents purely physiological functions. The next higher form of activity is that which occurs through the medium of sensation, the lower form of consciousness, and represented by the line BEAC. The activity of the centre E operates to inhibit the unconscious reflex and to place muscular action under the impulse created by sensation. We have here a higher order of action. Still the creature manifesting it is not said to be free, although conscious, because the connection between E and C seems as immediate and direct as between B and C. That is, the animal acts upon the impulse of the moment, and without reflection. The sensation to all appearances is the cause of the volition in such cases, and inasmuch as the stimulus at B is beyond all control or determination by the subject, namely, is the effect of external impressions, and also the sensation at E being a pure sensory reflex, the supposition that the sensation or emotion, as it no doubt does in many cases, acts directly and efficiently to produce a motor discharge through EAC makes the motive a purely efficient cause instead of admitting the characteristic of a final cause as a part
