i6 Studies in Animal Behavior 



that their activities are entirely determined by their 

 bodily organization without knowledge or will of 

 their own, was simply the result of carrying out to 

 its full logical consequences the mechanistic physi- 

 ology that he had adopted. "I have diligently en- 

 quired," he says, "whether all the motions of ani- 

 mals came from two principles, or only from one ; 

 and as I find it clear that they arise from that prin- 

 ciple alone which is corporeal and mechanical, I can 

 by no means allow them to have a thinking soul. 

 Nor am I at all hindered in this conclusion, by the 

 cunning and sagacity of foxes and dogs, nor by those 

 actions done from lust, hunger or fear; for I pro- 

 fess to be able easily to explain all these things by 

 the sole conformation of their limbs." 



Although Descartes explained by a physical mech- 

 anism what had been previously ascribed to the sen- 

 sitive soul, his conclusion was equally acceptable to 

 most of the dignitaries of the church, inasmuch as 

 it preserved an essential distinction between the brute 

 creation and man. In fact this disposition of the 

 animal world was hailed with satisfaction by many 

 church authorities, and it was rapidly followed by 

 various writers several of whom developed even 

 more extreme views. Malebranche, for instance, 

 tells us that "Among cats and dogs and other ani- 

 mals there is no intelligence, no spiritual soul as we 

 are commonly told. They eat without pleasure, cry 

 without pain. They grow without knowing it; they 

 desire nothing; they know nothing, and if they act 



