viii DARWINISM AND DESIGN 137 



these additional factors in determining both what sort of 

 variations can occur, and in what directions organisms 

 can vary, can hardly be disputed. Yet this admission 

 would seem to be a sufficient refutation of the extreme 

 claim that Natural Selection alone is competent to 

 account for everything and exhausts the list of the factors 

 in organic evolution which are logically admissible. 



It follows that if the Darwinian factors are not an 

 adequate and complete account of what really happens, 

 we are at liberty to supplement them by any additional 

 factors we may require. Some such factors, such as 

 geographical isolation, are, of course, admitted even by 

 the ultra-Darwinians ; others, like sexual selection and 

 the inherited effects of use and disuse, were adopted by 

 Darwin himself; others, again, like the sensibility of 

 organisms and their conscious efforts to attain their ends, 

 are at least tolerated as worth discussing. What part, if 

 any, these factors actually play in the history of organisms 

 is still sub judice and cannot here be determined. It is 

 enough for the present argument that Darwinism is not 

 entitled to bar them out a priori as methodologically 

 inadmissible. For if they are not inadmissible, a breach 

 is made in the iron barrier with which the original con 

 ception of a mechanically complete Darwinism shut out 

 every possibility of teleology. It is so far attenuated 

 that it can no longer reject a priori the suggestion of the 

 possibility of one more teleological factor, viz. of a 

 purposive direction of the course of variation. Such a 

 purposive direction would still be hard to prove, because 

 its action would be cloaked under a mass of other causes 

 of variation, and because it would perhaps only display 

 itself clearly in the occurrence of variations leading on to 

 new species or new eras ; but it would no longer be unthink 

 able, and that would be no slight step towards a teleology. 



III. It has been shown so far that if Darwinism is, as 

 may easily be done, made into a dogmatic denial of the 

 share of intelligence in Organic Evolution and of the 

 admissibility of determinable causes, of a limited number, 

 and of a definite direction of variations, it is demonstrably 



