CHAPTER XIII 



INSTINCT AND REASON 



If a frog's spinal cord be divided at the neck and a 

 drop of strong acid be placed on his thigh he will 

 bend his leg and rub it off with his foot. The brain 

 can give him no help, for the connection has been 

 severed. Only some lower nerve centre is called into 

 play, and there is no consciousness. It is such action 

 that we call reflex. If we accidentally touch hot em- 

 bers, then suddenly draw back, the action of drawing- 

 back is as reflex as the frog's movement of his leg. So 

 far all is easy. But no one can approach the subject 

 of instinct and reason without feeling that it is an 

 extremely difficult one. An instinctive action is 

 different from a merely reflex one in this, that it 

 originates with the brain, and is probably accom- 

 panied by consciousness, though there is no conscious 

 working towards an object in view. When a hungry 

 Blackbird sees a worm he at once proceeds to eat it 

 without going through a process of reasoning. But 

 he is probably conscious, all the while, what he is 

 doing. It is, therefore, an instinctive and not a 



