XIV BIOLOGICAL SCIENCES AND MEDICINE 357 



physiological processes among the higher animals ; 

 "while, indirectly, their influence was perhaps even 

 more remarkable. 



But, though Harvey made this signal and peren- 

 nially important contribution to the physiology of 

 the moderns, his general conception of vital pro- 

 cesses was essentially identical with that of the 

 ancients ; and, in the " Exercitationes de genera- 

 tione," 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 pro- 

 duct 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 suppose that a process is ex- 

 plained 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 



