Annual Address by the President. 
7 
istence of a creative vital force, that has power to generate from organic 
matter the organs which constitute the living being as a whole. 
Meanwhile, however, atomic mechanics, originated and elaborated by 
the great philosophers and scientists of the 17th Century, and extended 
as an adequate explanation to the entire domain of perceptible nature, 
became more and more exclusively the creed of many naturalists. Gas- 
sendi had revived epicurean atomics. Descartes, inspired by Harvey’s 
discovery of the circulation of the Wood, was led to look upon the living 
organism as, out and out, a mere automatic machine mechanically actu- 
ated. Death, to him, meant no longer the separation of the vital princi- 
ple from the material body, but simply the breaking up of the bodily 
machine. 
Soon all activity in nature was regarded by most scientists as the 
result of mechanical impact applied to inert matter. Imparted motion 
was held to be the sole spring of action. And all bodily forms and 
structures were, under this aspect, necessarily held to result from the 
mere spatial groupings and acquired motions of the atoms composing 
them. 
Robert Boyle, the founder of scientific chemistry, fully adopted the 
atomo-mechanical view as the true explanation of natural phenomena. 
And Newton in his ever memorable “Principia,” expounded it mathe- 
matically with consummate precision and completeness. Among physi- 
cists, at least, there remained henceforth no doubt that perceptible na- 
ture consists altogether of material particles moved more or less swiftly, 
and grouped more or less compactly and orderly by imparted motion 
under mechanical laws. To them atomic mechanics was no mere work- 
ing hypothesis, but a true interpretation of what really exists. These 
materialistic and mechanical conclusions followed, indeed, necessarily 
from the assumption of inert, indestructible atoms as the veritable build- 
ing-material of the universe. 
In the 18th century the physical materialism of the 17th expanded 
into general philosophical materialism, which reached its culmination 
in Lamettrie’s “Homme Machine” and in Holbach’s “System de la Na- 
ture,” where even mental phenomena were declared to result from ma- 
terial motions. 
Physiologists, however, in face of the marvelous manifestations of life, 
very generally resisted the purely mechanical interpretation. They could 
not yet see their way to dispense with the conception of a special vital 
principle in the explanation of the phenomena they were studying. It 
was not until the appearance of Lotze’s celebrated article in Wagner’s 
“Handworterbuch der Physiologie,” that the ancient Vitalism was over- 
come by being shown to be grounded on nothing but metaphysical fic- 
