DARWIN'S PLACE IN FUTURE BIOLOGY 39 



Again, a phenomenon of organisms that Darwin appealed to in 

 elaborating his hypothesis is their prodigality in generation. He almost 

 always looked at this from the standpoint of the inevitable crowding 

 and struggle, carnage, famine and death, that result. 



But there is another direction from which this prodigality must be 

 viewed, namely, from that of the absolute interdependence, the recip- 

 rocal relationships that prevail among organisms. Though always con- 

 sumers, organisms are likewise always producers, and are producers in 

 larger measure titan is necessary for their own perpetuity and best 

 interests. " Every species is its own worst enemy." There is conse- 

 quently, on the whole, a surplusage of product as regards both the indi- 

 vidual and the kind. So it comes about that the consumption that is 

 going on is in part a consumption of surplus. Do not understand me 

 to say that this is the correct view of the matter while the other is incor- 

 rect. Both views are true, and hence exclusive or unbalanced attention 

 to either is inadequate. 



Our conclusion amounts to this : Darwin's fame will grow in luster 

 parsi passu with growing recognition that he did not discover the cause 

 of evolution. This paradoxical statement ought to be viewed askance, 

 as all paradoxes should be. But see its justification. We biologists 

 will be able to approach the important truth of struggle in animate 

 nature with minds open for evidence of every sort as to its meaning 

 when we shall have broken up the habit — for habit it has surely become 

 — of attributing to it powers and capabilities beyond those it actu- 

 ally has. 



We turn again to the greater side of Darwin's work. Transform 

 yourself in imagination to a state of mind that holds all the natural 

 kinds of plants and animals by which you are daily surrounded, to be 

 each an independent miraculous creation, to be objects, that is, con- 

 cerning the origin of which no human being shall ever gain the slightest 

 real knowledge. Thus transform yourself, and then, and only then, 

 may you grasp the momentous significance of the extension of the 

 domain of law in the physical world wrought by the establishment of 

 the " mere fact " of evolution. 



Since my position makes so much of the distinction between estab- 

 lishing the truth of evolution and discovering the adequate cause of 

 evolution I must justify myself more fully. Let us ask how sharply 

 Darwin himself made this distinction, and how he appraised his own 

 work from this standpoint. 



That Darwin was convinced of the fact of descent with modification 

 before he had any working hypothesis as to its cause, in other words, 

 that he was an evolutionist before he was a natural selectionist has not 

 been given due weight, though perhaps is well enough known. Let us 

 look briefly at the evidence for this statement. 



