The Metaphysics of Darwinism. 81 



tendency towards progressive and more perfect 

 development, it is only because the phrase seemed 

 to suggest an &quot; internal force beyond the ten 

 dency to ordinary variability,&quot; not that he* did 

 not agree with them in holding to some kind of 

 an &quot; inherent tendency to vary.&quot; 



This, then, is our first determination regarding 

 the variations which supply material for natural 

 selection to work upon. They originate, we know 

 not how, in the nature of the organism. Nor 

 would the state of the case be essentially altered 

 if it were demonstrated, in opposition to Darwin, 

 that every organic modification was occasioned 

 by some external stimulus. For the change thus 

 set up in the organism in response to the foreign 

 excitation would obviously derive its character 

 from the constitution of the organism, just as, to 

 use Darwin s own example, the peculiarity of a 

 flame is due to the constitution of the combustible 

 materials, and not to the igniting spark. 



So much of the origin of the variations. With 

 regard to their nature, it may be either definite 

 or indefinite. That is to say, the offspring of 

 individuals exposed to given conditions during 

 several generations may be modified in a similar 

 or a dissimilar manner. Indefinite variability is 

 the general rule, according to Darwin, who, in 

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