THE ALLEGED PROOF OF PARALLELISM FROM THE CONSERVATION OF ENERGY.
THE earlier protagonists of the doctrine of psycho-physical parallelism were content to rest their case upon a rather complicated argument from general analogy. The theory pre- sented itself as an hypothesis which seemed to be demanded by the continuity between reflex action and conscious voluntary action, and by the known facts of mental pathology. Its general accord with some of the most vital tendencies of scientific thought, as well as its simplicity and elegance from a philosophic standpoint, were additional reasons for its acceptance. But since its practical adoption as the working hypothesis of modern psy- chology, a more summary method of proof has become fashion- able. Like many scientific points of view originally established by careful induction, it has become an @ priori principle. We are now told that it follows necessarily from the principle of the conservation of energy, and to doubt it is to doubt the “grandest generalization of modern science.” Into this argu- ment it is my purpose to inquire. It will be my endeavor not merely to expose the fallacy of the bare argument as given, but, if possible, to make the discussion more psychological—to get at the real origin of this curious belief. I shall make my best effort to get at, and answer, the real thought that underlies the argu- ment, and not merely the argument itself as it stands. If I do not succeed in doing full justice to the supporters of the view, it will not be from failure to make every effort to see the problem as they see it. I trust then, whatever else I may be accused of, I shall not be accused of wilfully misrepresenting the argument I am attacking.
We may best approach the subject by taking a classical example of what may be termed an over-interpretation of the principle of the conservation of energy. It is frequently said that the laws of electro-magnetic induction can be deduced from the conservation of energy; and this is sometimes mentioned
