CHAP, xvii METAPHYSICS OF NATURAL SELECTION 193 



tors taken together give us the final result (b) selec- 

 tion. The immediate outcome of Darwin's theory as 

 a contribution to science is this, he needs no additional 

 factor. The factors already named suffice (he holds) 

 to account for the further result many distinct liv- 

 ing species. As a scientific worker, Darwin simply 

 postulates his small array of causes existing casually 

 alongside of each other. The man of science has no 

 need to search more deeply, and Darwin does not do so. 

 But, when natural selection is generalised as a philo- 

 sophical theory, when it is applied to other depart- 

 ments of existence, outside of and above biology, we 

 must raise deeper issues. We must not allow the as- 

 sumption to pass as matter of course, that the " ab- 

 stractions," which are legitimate and necessary in 

 special sciences, are facts, or are determining condi- 

 tions of all human thinking. Because you have skil- 

 fully dissected the world into a few separate limbs or 

 tissues, and can show exactly how they fit together, 

 it does not follow that no subtle " spiritual bond " has 

 eluded your scalpel. Because you can explain your 

 special problem without asking whether organism and 

 environment, organism and organism, force and force, 

 have any necessary relation to each other beyond the 

 bare fact of co-existence, it does not follow that you 

 have demonstrated the unreality of such a relation- 

 ship. You have assumed its non-existence or 

 rather you have ignored the whole question ; and 

 quite fairly for a special purpose. But you have 

 proved nothing. And the sceptical programme is 

 improbable, perhaps impossible; "mechanism made 

 absolute; chance the only nexus between the ele- 

 ments of nature ! " 



