THEORIES CONCERNING AXIOMS. 



177 



To speak next of the premises. 

 Our assurance of their truth, whether 

 they be generalities or individual 

 facts, is grounded, in Mr. Spencer's 

 opinion, on the inconceivableness of 

 their being false. It is necessary to 

 advert to a double meaning of the 

 word inconceivable, which Mr. Spen- 

 cer is aware of, and would sincerely 

 disclaim founding an argument upon, 

 but from which his case derives no 

 little advantage notwithstanding. By 

 inconceivableness is sometimes meant 

 inability to form or get rid of an idea ; 

 sometimes, inability to form or get rid 

 of a belief. The former meaning is 

 the most conformable to the analogy 

 of language ; for a conception always 

 means an idea, never a belief. The 

 wrong meaning of " inconceivable " is, 

 however, fully as frequent in philo- 

 sophical discussion as the right mean- 

 ing, and the intuitive school of meta- 

 physicians could not well do without 

 either. To illustrate the difference, 

 we will take two contrasted examples. 

 The early physical speculators con- 

 sidered antipodes incredible, because 

 inconceivable. But antipodes were 

 not inconceivable in the primitive 

 sense of the word. An idea of them 

 could be formed without difficulty : 

 they could be completely pictured to 

 the mental eye. What was difficult, 

 and as it then seemed impossible, 

 was to apprehend them as believable. 

 The idea could be put tc^ether of 

 men sticking on by their feet to the 



be admitted that, though mere oversights 

 in the syllogistic process, like errors of 

 addition in an account, are special to the 

 individual, and seldom escape detection, 

 confusion of thought produced (for ex- 

 ample) by ambiguous terms has led whole 

 nations or ages to accept fallacious reason- 

 ing as valid. But this very fact points to 

 causes of error so much more dangerous 

 than the mere length of the process, as 

 quite to vitiate the doctrine that the "test 

 of the relative vaUdities of conflicting con- 

 clusions " is the number of times the funda- 

 mental postulate is involved. Ou the con- 

 trary, the subject on v^hich the trains of 

 reasoning are longest, and the assumption 

 therefore, oftenest repeated, are in general 

 those which are best fortified against the 

 really formidable causes of fallacy ; as in 

 the example already given of roathematica 



under side of the earth ; but the 

 belief would follow that they must 

 fall off. Antipodes were not unima- 

 ginable, but they were unbelievable. 



On the other hand, when I endea- 

 vour to conceive an end to extension, 

 the two ideas refuse to come together. 

 When I attempt to form a conception 

 of the last point of space, I cannot 

 help figuring to myself a vast space 

 beyond that last point. The com- 

 bination is, under the conditions of 

 our experience, unimaginable. This 

 double meaning of inconceivable it is 

 very important to bear in mind, for 

 the argument from inconceivableness 

 almost always turns on the alternate 

 substitution of each of those meanings 

 for the other. 



In which of these two senses does 

 Mr. Spencer employ the term, when 

 he makes it a test of the truth of a 

 proposition that its negation is incon- 

 ceivable? Until Mr, Spencer ex- 

 pressly stated the contrary, I inferred 

 from the course of his argument that 

 he meant unbelievable. He has, how- 

 ever, in a paper published in the fifth 

 immber of the Fortnightly Review, dis- 

 claimed this meaning, and declared 

 that by an inconceivable proposition 

 he means now and always, "one of 

 which the terms cannot, by any effort, 

 be brought before consciousness in that 

 relation which the proposition asserts 

 between them — a proposition of which 

 the subject and predicate offer an in- 

 surmountable resistance to union in 

 thought." We now, therefore, know 

 positively that Mr. Spencer always 

 endeavours to use the word inconceiv- 

 able in this, its proper sense : but it 

 may yet be questioned whether his 

 endeavour is always successful ; whe- 

 ther the other, and popular use of the 

 word does not sometimes creep in 

 with its associations, and prevent him 

 from maintaining a clear separation 

 between the two. When, for example, 

 he says, that when I feel cold I can- 

 not conceive that I am not feeling 

 cold, this expression cannot be trans- 

 lated into " I cannot conceive myself 

 not feeling cold," for it is evident that 



