526 THE THEORY OF ENERGY AND THE LIVING WORLD. 



of the ambient mentality. To a generation reared in admiration and 

 respect of the efforts of genius which have compassed the creation 

 of this system, they propose contempt for all its images, the symbols 

 or the material representations of scientific truth. They offer us, to 

 explain the natural phenomena, systems of three or six differential 

 equations, which to them contain no hypotheses. Whether the future 

 will sustain or condemn them we are not competent to prophesy. But 

 the main reason which deters us from the task, doubtless beyond our 

 powers of tracing the kinetic hypothesis, is that it is not essential for 

 our purpose. We merely propose to show in what follows how the 

 consideration of energy and of its first fundamental principle, that of 

 its conservation, have transformed the point of view of physiology on 

 three great questions, the conception of the vital phenomena in their 

 relation to the general phenomena of nature, the theory of alimenta- 

 tion, and finally the origin of muscular force. 



II. — THE ENERGY OF LIFE.' 



Despite the efforts of a small number of experimenters from Harvey to 

 Magendie, the science of life has been outstripped in the progress of the 

 other natural sciences. It remained a long time embalmed in scholastics 

 and incumbered by such systems as animism and vitalism, according to 

 which vital phenomena were governed by a principle distinct from the 

 physical forces, and thus their difference from other natural phenomena 

 was accentuated. 



These systems were dominant in the schools of the time of Lavoisier, 

 and still acted as a check on the experimental method in the time of 

 Claude Bernard. They have scarcely disappeared entirely even in our 

 day. In 1878 an eminent physician, who occupied one of the highest 

 positions of instruction, E. Chauffard, attempted to restore the animism 

 of Stahl. Still more recently we have seen discoveries of two foreign 

 scientists of legitimate reputation, Heidenhain, of Breslau, and Oh. 

 Bohr of Copenhagen, serving to resuscitate the name "neo- vitalism," a 

 doctrine much preached by those who in the last century supported 

 Bordeu and Barthez. The contemporaneous neo-vitalism borrowed 

 from its forerunner its fundamental principle, the unique character, not 

 only in form but in essence, of vitality, and its absolute irreducibility to 

 anything physical. To be sure this was coupled in the ancient vitalism 

 with another notion which the progress of ideas did not permit to be 

 revived in our time. It considered physiological phenomena to be the 

 immediate effect of a special cause, an agent of some sort personified, 



'References: A. Cbauveau; La Vie et l'Energie chez l'animal, 1894. La Valeur 

 6nerg6tique des aliineus (Acadernie des sciences), 1897. F. Lauianie: Energotique 

 musculaire, 1898. J. Loeb: La Physiologie ge"n£rale, son but et sonliistoire (Pflnger's 

 Archiv), 1898. A. Gautier: Lecons de chimie biologique, 1897. 



