334 THE BIOLOGICAL SCIENCES AND MEDICINE. [LECT. 



moderns, his general conception of vital processes 

 was essentially identical with that of the ancients; 

 and, in the " Exercitationes de generatione," and 

 notably in the singular chapter " De calido innato," 

 he shows himself a true son of Galen and of Aristotle. 



For Harvey, the blood possesses powers superior 

 to those of the elements ; it is the seat of a soul which 

 is not only vegetative, but also sensitive and motor. 

 The blood maintains and fashions all parts of the 

 body, " idque summa cum providentia et intellectu in 

 finem certum agens, quasi ratiocinio quodam uteretur." 



Here is the doctrine of the " pneuma," the product 

 of the philosophical mould into which the animism of 

 primitive men ran in Greece, in full force. Nor did its 

 strength abate for long after Harvey's time. The 

 same ingrained tendency of the human mind to sup- 

 pose that a process is explained when it is ascribed 

 to a power of which nothing is known except that it 

 is the hypothetical agent of the process, gave rise, in 

 the next century, to the animism of Stahl ; and, later, 

 to the doctrine of a vital principle, that "asylum 

 ignorantiae" of physiologists, which has so easily 

 accounted for everything and explained nothing, 

 down to our own times. 



Now the essence of modern, as contrasted with 

 ancient, physiological science appears to me to lie in 

 its antagonism to animistic hypotheses and animistic 

 phraseology. It offers physical explanations of vital 

 phenomena, or frankly confesses that it has none to 

 offer. And, so far as I know, the first person who 

 gave expression to this modern view of physiology, 



