DARWIN AND HIS HYPOTHESES 75 



the Coral Reefs, I cannot remember a single first-formed 

 hypothesis which had not after a time to be given up or 

 greatly modified. This has naturally led me to distrust 

 greatly deductive reasoning in the mixed sciences.' l 



It is impossible on the present occasion to 

 attempt any analysis of Darwin's genius. I wish, 

 however, to show how clearly he recognized that 

 the love of knowledge for its own sake was the 

 one essential qualification for a scientific man. 

 In his autobiography (1881) he puts ' the love 

 of science ' first among the qualities to which 

 he owed his success. 2 But far earlier in his life, 

 when he was under 40, Darwin wrote to his old 

 teacher Henslow : 



' I rather demur to one sentence of yours viz., '* However 

 delightful any scientific pursuit may be, yet, if it should be 

 wholly unapplied, it is of no more use than building castles 

 in the air." Would not your hearers infer from this that 

 the practical use of each scientific discovery ought to be 

 immediate and obvious to make it worthy of admiration ? 

 What a beautiful instance chloroform is of a discovery made 

 from purely scientific researches, afterwards coming almost 

 by chance into practical use ! For myself I would, however, 

 take higher ground, for I believe there exists, and I feel 

 within me, an instinct for truth, or knowledge or discovery, 

 of something of the same nature as the instinct of virtue, 



1 Life and Letters, i, 103, 104. See also 149, where Mr. Francis 

 Darwin states : ' It naturally happened that many untenable 

 theories occurred to him ; but fortunately his richness of imagina- 

 tion was equalled by his power of judging and condemning the 

 thoughts that occurred to him. He was just to his theories, and 

 did not condemn them unheard . . .' 



2 Life and Letters, i. 107. See also 103, where he says (1881) : - 

 ' What is far more important [ihan powers of observation, industry, 

 &c.], my love of natural science has been steady and ardent. 

 This pure love has, however, been much aided by the ambition to 

 be esteemed by my fellow naturalists.' 



