The Commonplace 31 



edge of some special part of it. One assuredly 

 cannot be zoologist, geologist, botanist, and 

 meteorologist ; but if he has intimate personal 

 knowledge of one limited part, he has the 

 key to the whole. The person must have 

 pursued some branch of natural history for 

 a time with serious purpose, the purpose to 

 discover and to know the subject-matter for 

 himself. This gives him point of view ; tells 

 him what to look for ; enables him to look 

 beneath the surface ; trains his judgment as to 

 causes and effects ; guides him in distinguish- 

 ing the essential ; saves him from error. 



But before one takes up any serious bit 

 of study for himself, he must have the wish 

 to take it up. In every person there is a 

 latent desire to know something of the en- 

 closing world, but it is usually ironed out in 

 the laundering processes of the schools and the 

 misdirections of the home. In some persons 

 this native desire is so strong that nothing 

 extinguishes it: these persons become pro- 

 fessional investigators and widen the boundaries 

 of knowledge. Most of us, however, must 



