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 
