12 Studies in Animal Behavior 



feeding, for in these two acts all their interests and 

 life concentrate," recalls the aphorism of Schiller 

 that hunger and love are the ruling forces of the 

 world. Aristotle was very far from regarding be- 

 havior as determined by external stimulation. He 

 had no conception of reflex action, no knowledge of 

 the function of nerves, and he regarded the brain as 

 an organ to temper the heat of the heart, the lat- 

 ter being considered as the seat of sensation. 



The doctrine that animals reason found an ardent 

 defender in Plutarch, who devotes two rather curious 

 chapters of his "Morals" to a consideration of the 

 mental powers of animals and their relation to the 

 faculties of men. Different views are put forward 

 in dialogue form much after the fashion of Plato. 

 The discussions are of interest mainly as present- 

 ing the views of animal intelligence current in Plu- 

 tarch's time. Porphyry's views of animals were 

 much like those of Plutarch, although they were 

 interwoven with his Neo-Platonist doctrines concern- 

 ing the nature of the soul. 



The Romans, like the Greeks, were generally in- 

 clined to give credit to the lower animals for a 

 considerable amount of intelligence. Pliny with his 

 usual uncritical judgment related many stories of 

 wonderful animal sagacity, and Celsus contended 

 for the essential similarity of mind in brute and man. 

 Galen shows an approach to the conception of in- 

 stinct as it came to be understood by later writers. 

 He dwelt at length on the adaptations of the struc- 



