THEOEIES CONCEKNING AXIOMS. 208 



It is but just to give Mr. Spencer's doctrine the benefit of the limitation 

 he claims — viz., that it is only applicable to propositions which are assented 

 to on simple inspection, without any intervening media of pi'oof. But this 

 limitation does not exclude some of the most marked instances of proposi- 

 tions now known to be false or groundless, but whose negative was once 

 found inconceivable : such as, that in sunrise and sunset it is the sun which 

 moves; that gravitation may exist without an intervening medium; and 

 even the case of antipodes. The distinction drawn by Mr. Spencer is real ; 

 but, in the case of the propositions classed by him as complex, conscious- 

 ness, until the media of proof are supplied, gives no verdict at all: it nei- 

 ther declares the equality of the square of the hypothenuse with the sum 

 of the squares of the sides to be inconceivable, nor their inequality to be 

 inconceivable. But in all the three cases which I have just cited, the in- 

 conceivability seems to be apprehended directly ; no train of argument was 

 needed, as in the case of the square of the hypothenuse, to obtain the ver- 

 dict of consciousness on the point. Neither is any of the three a case like 

 that of the school-boy's mistake, in which the mind was never really brought 

 into contact with the proposition. They are cases in which one of two op- 

 posite predicates, mero adsjyectu, seemed to be incompatible with the sub- 

 ject, and the other, therefore, to be proved always to exist with it.* 



As now limited by Mr. Spencer, the ultimate cognitions fit to be submit- 

 ted to his test are only those of so universal and elementary a character as 

 to be represented in the earliest and most unvarying exj)erience, or appar- 

 ent experience, of all mankind. In such cases the inconceivability of the 

 negative, if real, is accounted for by the experience : and why (I have ask- 

 ed) should the truth be tested by the inconceivability, when we can go fur- 

 ther back for proof — nam'ely, to the experience itself ? To this Mr. Spen- 

 cer answers, that the experiences can not be all recalled to mind, and if re- 

 called, would be of umnanageable multitude. To test a proposition by ex- 

 perience seems to him to mean that " before accepting as certain the prop- 

 osition that any rectilineal figure must have as many angles as it has sides," 

 I have " to think of every triangle, square, pentagon, hexagon, etc., which I 

 have ever seen, and to verify the asserted relation in each case." I can 

 only say, with surprise, that I do not understand this to be the mtaning of 

 an appeal to experience. It is enough to know that one has been seeing 

 the fact all one's life, and has never remarked any instance to the contrary, 

 and that other people, with every opportunity of observation, unanimously 

 declare the same thing. It is true, even this experience may be insufticient, 

 and so it might be even if I could recall to mind every instance of it; but 



* In one of the three cases, Mr. Spencer, to my no small sui-prise, thinks that the helief of 

 mankind "can not be rightly said to have undergone" the change I allege. Mr. Spencer 

 himself still thinks we are unable to conceive gravitation acting through empty space. "If 

 an astronomer avowed that he could conceive gravitative force as exercised through space ab- 

 solutely void, my private opinion would be that he mistook the nature of conception. Con- 

 ception implies representation. Here the elements of the representation are the two bodies 

 and an agency by which either affects the other. To conceive this agency is to represent it 

 in some terms derived from our experiences — that is, from our sensations. As this agency 

 gives us no sensations, we are obliged (if we try to conceive it) to use symbols idealized from 

 our sensations — imponderable units forming a medium." 



If Mr. Spencer means that the action of gravitation gives us no sensations, the assertion is 

 one than which I have not seen, in the writings of philosophers, many more startling. What 

 other sensation do we need than the sensation of one body moving toward another? "The 

 elements of the representation" are not two bodies and an "agency," but two bodies and an 

 effect ; viz., the fact of their approaching one another. If we are able to conceive a vacuum, 

 is there any difficulty in conceiving a body falling to the earth through it ? 



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