CHANGES IN SCIENTIFIC OPINION 17 



" the principle of life in the lower animals was 

 held by the schoolmen to be an example of 

 a simple principle which is nevertheless not 

 spiritual, since it is altogether dependent upon 

 the organism, or, as they said, completely im- 

 mersed in the body. St Thomas accordingly 

 speaks of the corporeal souls of brutes." In 

 fact the scholastic philosophy assigned what is 

 called " souls," sensitive and vegetative souls, 

 to vegetables as well as to the lower animals, 

 and by that term " soul " signified that prin- 

 ciple of life which, as vitalists hold, is the 

 factor the elusive but none the less certainly 

 existent factor which distinguishes living from 

 non-living matter, which places the simplest of 

 organisms, say the microscopic Amoeba, in a 

 position separated by a gulf of immeasurable 

 width from the most complicated product or 

 substance of the inorganic world. Such in 

 essence was the view at the period in question, 

 and it is a theory which, unlike that of the 

 alchemists, has never ceased to have its 

 adherents. 



In a succeeding chapter the views of 

 scholastic philosophy on this question will be 

 briefly detailed : meantime it is perhaps hardly 

 necessary t>. ' say that writers of this school 

 were unanimously vitalistic. This continued 

 to be true c^ what some would call the end of 



B 



