432 PHYSIOLOGY 



heart, I cannot see to be matter or force or any conceivable modifi- 

 cation of either." It is perhaps a question of terms only as to whether 

 this point of view is properly designated as vitalism. Inasmuch, 

 however, as it assumes a something that can be influenced only by 

 living matter, possibly only by special forms of living matter, and 

 in turn can only act upon living matter, it draws a line between 

 the properties of the animate and the inanimate which represents 

 a real distinction, and those who hold to this point of view or any 

 modification of it can scarcely escape, for want of a better term, the 

 designation of vitalist, even though it is recognized that the reaction 

 between the subjective and the objective world may be governed 

 by laws that are, strictly speaking, as mechanical as those reactions 

 of matter that have been generalized under the laws of physics and 

 chemistry. In this sense I believe that the majority of physiologists 

 belong to the school of vitalists. The methods that they employ 

 and the nomenclature they use are, however, mechanical, because 

 the science recognizes that its ultimate aim is to understand the 

 mechanics of living matter, and that in this way only, if at all, shall 

 we be able to arrive at a conception of the relations of this matter 

 to a reality of a different order. The older physiologists, and some 

 of recent times, have used the conception of vitalism as a convenient 

 and easy means of accounting for many processes which further 

 investigation has shown to be purely mechanical. Experiences of 

 this kind tend to strengthen our belief that most of the unknowns 

 confronting us at present will be analyzed eventually in terms of the 

 conceptions of physics and chemistry; but there is always present 

 in physiology the tendency to assume that what is not clearly or 

 conceivably reducible to the laws of matter and energy must there- 

 fore belong to the "irreducible residuum." The nature of this 

 residuum, the connotation of the term vitalism, varies somewhat 

 with each generation. 



Bernard, in his lucid and masterly discussion of the phenomena 

 of life, came to the conclusion that the irreducible residuum, to which 

 the laws of chemistry and physics are not and cannot be applicable, 

 is the power of development of the egg. "Car il est clair que cette 

 proprie'te' Evolutive de Poeuf, qui produira un mammifere, un oiseau, 

 ou un poisson, n'est ni de la physique ni de la chimie. ... La 

 force Evolutive de 1'oeuf et des cellules est done le dernier rempart 

 du vitalisme." * In our own day the study of the mechanics of devel- 

 opment is actively pursued by many investigators, and I fancy that 

 few modern physiologists are inclined to take a truly vitalistic 

 view of the process. However much the facts of development are 

 beyond the possibility of explanation in terms of our present 

 chemico-physical knowledge, it is clearly conceivable that the 

 1 Bernard, Revue des Deux Mondes, ix, p. 326, 1875. 



