196 FROM FISH TO PHILOSOPHER 



of the brain— the difficulty lies in explaining its lack of 

 plasticity. Thomas R. Lounsbnry, a nineteenth-century 

 professor at Yale's Sheffield Scientific School, was not far 

 wrong when he remarked that we must view with pro- 

 found respect the infinite capacity of the human brain 

 to resist the introduction of useful knowledge. Granting 

 the force of this sardonic comment, by way of explana- 

 tion it must be emphasized that the brain is basically 

 just as conservative as any organ in the body: it works 

 by repetition, and an organ that works by repetition can 

 only learn by repetition— by being forcibly inscribed with 

 new channels. Man differs from the other vertebrates in 

 that he has, in some measure, learned how to learn. 



