Page:Mind (New Series) Volume 9.djvu/265

JAMES WABD, Naturalism and Agnosticism. 251 kinetics. From the general principles of kinetics Prof. Ward proceeds to the examination of the special principle of the Con- servation of Energy, and its supposed bearing upon the relation of mind to body as well as upon the question of human freedom. So much mischief has been done in psychology by misunderstand- ings about the meaning and scope of this principle that a discussion of it from the pen of one who is at once a psychologist and a metaphysician is exceedingly timely. It is to be hoped that Prof. Ward's treatment of the subject will make it impossible for psy- chologists in the future to repeat the blunder of assuming that the " Conservation of Energy " excludes the action of mind on body, or the possibility of intelligent self-determination. If the principle in question is to be taken as finally establishing " Natu- ralism," we must be prepared to assume (1) that the principle is of universal validity, (2) and further, apparently, that all energy is strictly kinetic. Both these assumptions are only too commonly made by psychologists as well as by certain " scientific men " without serious consideration of what they involve. Both are however, as Dr. Ward has little difficulty in showing, entirely unwarranted. We have no right, in the first place, to assume without proof, that there is any such thing as " the physical universe," that is, as a material system rigidly governed by mechanical laws and complete in itself, or that, if there is, the stock of energy it possesses is finite. And, in the second place, we have no right to assume that all energy is kinetic. In the author's language, the law of " Conservation " is essentially a law of exchanges ; it tells us merely, that in the various transforma- tions of energy the quantity remains the same ; it has nothing to say as to the number of such possible transformations or their specific nature. Once more, we are dealing with calculation, with mathematical constants, not with concrete realities. And again, the systems for which the validity of the law can be established are all finite parts of the real world, and its validity for them is thus no justification for assuming its applicability to the "world" or " physical universe " as a whole. So far it seems impossible to differ from Prof. Ward or to improve on his statement of the case. There are however certain portions of his treatment of the doctrine of Energy which seem fairly open to criticism. Take first of all the question whether the doctrine of Conservation is a " real " or a " formal " postulate of science. On this point Dr. Ward seems to speak with an uncertain voice. At page 175 of volume i. he appears to identify the principle with that of causality and sufficient reason, quoting with qualified approval Mayer's statement of it, causa cequat effectum, and speaking of it by implication as " not a logical or a mathematical, but a real principle ". At page 214 on the other hand we read that " the conservation of energy is not a law of change, still less a law of qualities . . . it is entirely a quan- titative law. . . . This principle may be regarded as primarily and fundamentally logical." The views set forth in these passages