moral and social order. The fear is exaggerated and chimerical; but that is not the point to be considered. A fact is always a fact, whatever may be the consequences. The question is, whether it is true: the student should recognize no other. Many of the facts encountered in our studies are obscure and hard to explain, but that does not prevent their being facts; or at least the chief question should be, to learn whether they are facts. Besides, contradictory facts are the ferment of science. I once asked a distinguished man of science how a certain discovery he had made was getting on. "It is not getting on," he replied. "What is the matter with it?" I anxiously asked. "Why," he said, "I find no facts except those which are favorable to it; and," he added, "it takes contradictory facts to teach us. This is true. The theory will either explain the contradictory facts and be fortified by them as the Newtonian theory has been by all the exceptions that have been opposed to it and which have entered into it; or it will be replaced by a wider and more comprehensive theory. In both cases there is a gain for science, which would not have been obtained if we had hesitated, on account of vain scruples, to seek out and verify the facts in question. In principle, every science should be independent of those which come after it. Chemistry, for example, whether organic or physiological, in studying the chemical conditions of life, is held to one thing only—to seek out and discover those chemical conditions—and has no other function. It is not for it to occupy itself with the interests of vital force nor with anything that concerns the vital. Its right and duty are to push as far forward as possible the chemical explanation, for who else is to do it? Then comes the physiologist. His business is to bring into the light the new element which has been added to the former. Chemistry could have been preoccupied with this only to its detriment. If chemistry had been concerned to take care of the existence of the vital principle, it would not have achieved the splendid discovery of organic synthesis which has made the name of M. Berthelot illustrious. Does this signify that life is not a chemical fact? Not at all. But it belongs to physiology, and not to chemistry, to exhibit the peculiar quality that distinguishes the one science from the other.
Applying these principles to psycho-physiology, all the clouds that obscure the question are dispelled. The function of psychophysiology is not to establish the existence of the soul; that belongs to pure psychology and metaphysics. How can we expect to find the soul, personality, freedom, in the study of the organs? The interests of the soul would therefore be very badly placed in the hands of psycho-physiology. They are better confided to other hands; and in touching upon these higher questions, that branch would be doing an injury to the cause which it assumed to serve.
