180 EEASONING. 



simple inspection, we can not so much as call up in our imagination two 

 straight lines, in order to attempt to conceive them inclosing a space, with- 

 out by that very act repeating the scientific experiment which establishes 

 the contrary. Will it really be contended that the inconceivableness of the 

 thing, in such circumstances, proves any thing against the experimental or- 

 igin of the conviction ? Is it not clear that in whichever mode our belief 

 in the proposition may have originated, the impossibility of our conceiving 

 the negative of it must, on either hypothesis, be the same ? As, then. Dr. 

 Whewell exhorts those who have any difiiculty in recognizing the distinc- 

 tion held by him between necessary and contingent truths, to study geom- 

 etry — a condition which I can assure him I have conscientiously fulfilled — 

 I, in return, with equal confidence, exhort those who agree with him, to 

 study the general laws of association ; being convinced that nothing more 

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

 sion which ascribes a peculiar necessity to our earliest inductions from ex- 

 perience, and measures the possibility of things in themselves, by the hu- 

 man capacity of conceiving them. 



I hope to be pardoned for adding, that Dr. Whewell himself has both 

 confirmed by his testimony the effect of habitual association in giving to 

 an experimental truth the appearance of a necessary one, and afforded a 

 striking instance of that remarkable law in his own person. In his Philos- 

 ophy of the Inductive Sciences he continually asserts, that propositions 

 which not only are not self-evident, but which we know to have been dis- 

 covered gradually, and by great efforts of genius and patience, have, when 

 once established, appeared so self-evident that, but for historical proof, it 

 would have been impossible to conceive that they had not been recognized 

 from the first by all persons in a sound state of their faculties. " We now 

 despise those who, in the Copernican controversy, could not conceive the 

 apparent motion of the sun on the heliocentric hypothesis ; or those who, 

 in opposition to Galileo, thought that a uniform force might be that which 

 generated a velocity proportional to the space; or those who held there 

 was something absurd in Newton'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 can not help thinking that men must have been 

 singularly dull of comprehension, to find a difficulty in admitting what is 

 to us so plain and simple. We have a latent persuasion that we in their 

 place should have been wiser and more clear-sighted ; that we should have 

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

 ality such a persuasion is a mere delusion. The persons who, in such in- 

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

 from being persons more prejudiced, or stupid, or narrow-minded, than the 

 greater part of mankind 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 imagine the struggle to 

 have been necessary. The very essence of these triumphs is, that they lead 

 us to regard the views we reject as not only false but inconceivable.''^* 



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

 in order to overthrow the whole theory of its author on the nature of the 



* Novum Organum Renovatum, pp. 32, 33. 



