zoologist learns to view his great common-sensible princi- 

 ples like the doctrine of descent, not as absolute eternal 

 verities, but only as summaries up to date, as working pro- 

 grams, to employ Professor Wilson's concise phrase. This 

 may be pragmatism ; it is certainly science. 



But surely this does not mean that principles like the one 

 mentioned are so many gratuitous assumptions. Like the 

 principle of gravitation and the law of the conservation of 

 energy, zoological laws have the strength and approximate 

 finality of all the wide range of facts that they summarize. 

 And these are many a vast store of detail and generaliza- 

 tion accumulated during decades and centuries by those 

 who have sought upon the mountains or in the abysses of 

 the seas for new knowledge, by countless students who 

 have spent their lives in the field and in the laboratory in 

 the endeavor to pierce still further with trained insight 

 into the mysteries of nature. And these are their results. 



No one realizes more than the zoologist that his know- 

 ledge is incomplete. No one can see more clearly than he 

 that his intellect evolves, like the great sweeping tide 

 of things and events the nature he studies and of which 

 he is but a conscious atom. The investigator soon learns to 

 withhold final judgment, agreeing with Clifford that the 

 primary conditions for intellectual development are the 

 plasticity and openness of mind that dogmatism and final- 

 ity destroy. The end of zoology cannot be until the end of 

 all knowledge. 



Conscious then of the impossibility of reaching abso- 

 lutely final knowledge, why does the investigator continue 

 to search the world of nature as he does ? Because of that 

 ingrained and insatiable human curiosity to learn, because 

 of the human discontent with the attained. Antaeus-like, 

 every fresh contact with the world of law and order infuses 

 new energy into his veins for further endeavor. "Und es 

 treibt und reisst ihn fort, rastlos fort ..." not, it is true, 



35 



