EVOLUTION THE MASTER-KEY 



" One might have supposed that as a needful preliminary 

 to a systematic discussion especially a discussion con- 

 cerning the nature of things the disputants would 

 agree on some method of distinguishing propositions 

 which must be accepted from propositions which it is 

 possible to deny. May not one fairly say that those who 

 decline to accept a test proposed, and also decline to 

 furnish a test of their own, do so because they are half 

 conscious that their opinions will not bear testing?" 



What, then, is Spencer's ultimate criterion of 

 belief? It is simply that "in the last resort we 

 must accept as true a proposition of which the nega- 

 tion is inconceivable." The inconceivability of its 

 negation is our ultimate criterion 1 of a certainty. 

 Now we must consider what Spencer means by 

 the word inconceivable. One academic critic, whose 

 helplessness almost excites sympathy, feeling him- 

 self bound to offer what opposition he may to any 

 Spencerian dictum, can find nothing more to say 

 than that Spencer fails to distinguish between 

 inconceivable and unimaginable. But Spencer 

 does distinguish ; and the distinction is to be found 

 enforced not once but often in his writings. It is 

 true that he does not use the confusing and ques- 

 tion-begging term unimaginable; but no one was 

 ever clearer than he is in condemning what he calls 

 a pseud-idea. And the unimaginable is distinct 

 from the inconceivable only when a pseud-idea, 

 as that of a moral fluid, is involved. Let us take 

 an instance. 



1 " Our ultimate criterion " not, alas, an absolute or infallible 

 criterion. 



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