294 The Origin of a "Thing' and its Nature 



'retrospective,' that it gives us some suggestions concerning 

 the very obscure concept called potency or 'potentiality.' 

 This soi-disant concept or notion has been used by almost 

 every conceivable shade of thought as the repository of that 

 which is unexplained. Aristotle started the pursuit of this 

 notion and used it in a way which shed much light, it is 

 true, upon the questions of philosophy concerned with 

 change and organization ; but his failure to give any analy- 

 sis of the concept itself has been an example ever since to 

 lesser men. It is astonishing that, with all the metaphysics 

 of causation which the history of philosophy shows, there 

 has been that is, to my knowledge- -no thoroughgoing 

 attempt to trace the psychological meaning of potentiality. 

 How common it is to hear the expression, ' this thing exists, 

 not actually, but potentially,' given as the end of debate - 

 and accepted, too, as the end. I do not care to go now 

 into a historical note on the doctrine of potentiality ; it 

 would be indeed mainly an exposition of a chapter of Aris- 

 totle's metaphysics with the refinements on Aristotle due 

 to the logic of the schoolmen and the dogmatics of modern 

 theology. It may suffice to say something of the natural 

 history of the distinction between potential and real exist- 

 ence in the light of the positions taken above. 



In brief, then, as we have seen, there are two aspects 

 under which reality must in all cases be viewed, the pro- 

 spective and the retrospective. The retrospective, as has 

 been said, is the summing up of the history which gives 

 positive content to the notion of a thing considered as 

 accomplished career. This aspect, it seems clear, is what 

 we have in view when we speak of ' real ' in contrast with 

 'potential' existence. It is not, indeed, adequately rendered 

 by the content supplied by retrospect, since the fact that 



