VOICES OF EXPERIENCE 



proved in the past to be mistaken. There is always room 

 for constructive questioning of even the most well estab- 

 lished theories. Who knows what current beliefs may 

 be shown to be as much in need of revision as the 

 nineteenth-century view that bats felt their way through 

 dark caves by some sense of touch residing in their 

 wings? 



33 



