DEMONSTRATION, AND NECESSARY TRUTHS. 159 



very act repeating the philosophical experiment whicli establishes the 

 contraiy. Will it really be contended thSt t>he inconceivableness of 

 the tliiuff, under such circumstances, proves anything against the ex- 

 perimental origin of the conviction I Is it not clear that in whichever 

 mode our beUef in the pi'oposition may have originated, the impossi- 

 bility of our conceiving the negative of it must, under either hypothesis, 

 be tJic same ? As, tlien, Mr. Whewell oxliorts those who have any 

 difficulty in recognizing the distinction held by him between necessary 

 and contingent ti'uths, to study geometry — a condition which I can 

 assure him I have conscientiously fulfilled — I, in return, with equal 

 confidence, exhort those who agree with Mr. Whewell, to study the 

 elementary laws of association ; being convinced that nothing more is 

 requisite than a moderate familiarity with those laws, to dispel the 

 illusion which ascribes a peculiar necessity to our earliest inductioHS 

 fi'om experience, and measures the possibility of things in themselvea, 

 by the human capacity of conceiving them. 



I hope to be pardoned for adding, that Mr. "Wliewell himself has 

 both confirmed by his testimony the effect of habitual association in 

 giving to an experimental truth the appearance 6f a necessary' one, and 

 attbrded a striking instance of that remarkable law in his own person. 

 In h\s Philosajjhy of the Inductive Sciences he continually asserts, 'that 

 propositions which not only are not self-evident, but whicli we know to 

 have been discovered gradually, and by gieat efforts of genius and pa- 

 tience, have, when Once established, appeared so self-evident that, but 

 for historical evidence, it would have been impossible to conceive that 

 they had not been recognized from the first by all pereons in a sound 

 state of tlieir faculties. " We now despise those who, in the Coperni- 

 can controversy, could not conceive the appai'ent motion of the sun on 

 the heliocenti'ic hypothesis; or those who, in opposition to Galileo, 

 thought that a uniform force might be tliat which generated a velocity 

 proportional to the space ; or those who held there was something ab- 

 surd in N'ewtoii's doctrine of the different refrangibility of differently 

 colored rays ; or those who imagined that when elements combine, their 

 sensible qualities must be manifest in the compound; or those who were 

 reluctant to give up the distinction of vegetables into herbs, shrubs, and 

 trees. We cannot help thinking that men must have been singularly 

 dull of comprehension to fii|d a difficulty in admitting what is to us so 

 plain and simple. We have a latent perstiasion that we in their place 

 should have been Aviser and moro clear-sighted ; that we should have 

 taken the right side,. and given our assent at once to the truth. Yet in 

 reality such a persuasipn is a mere delusion. The persons who, in such 

 instances as the above, were on the losing side, were very far in most 

 cases from beiYig persons more prejudiced, or ,stupid, or naiTow-minded, 

 than the greater part of rpankind now are ; and the cause for which 

 they fought was far from being a manifestly bad one, till it had been so 

 decided by the result of the war. ... So complete has been the victory 

 of truth in most of these instances, that at present we can hardly ima- 

 gine die struggle to have been necessary. The very essence of these tri- 

 umphs is, that they lead us to regard tltc views we reject as not only false, 

 hut inconceivahle.^'* 



This last proposition is precisely what I contend for ; and I ask no 



* Philosophy of the Indwtive Sckivce^, vol. ij., p. 174. 



