Why Darwin succeeded 87 



such views had been promulgated ; and many must, as Huxley says, 

 have taken up his own position of "critical expectancy 1 ." 



Why, then, was it, that Darwin succeeded where the rest had 

 failed ? The cause of that success was two-fold. First, and obviously, 

 in the principle of Natural Selection he had a suggestion which would 

 work. It might not go the whole way, but it was true as far as it 

 went. Evolution could thus in great measure be fairly represented as 

 a consequence of demonstrable processes. Darwin seldom endangers 

 the mechanism he devised by putting on it strains much greater than 

 it can bear. He at least was under no illusion as to the omnipotence 

 of Selection ; and he introduces none of the forced pleading which in 

 recent years has threatened to discredit that principle. 



For example, in the latest text of the Origin 2 we find him saying: 

 " But as my conclusions have lately been much misrepresented, 

 and it has been stated that I attribute the modification of species 

 exclusively to natural selection, I may be permitted to remark 

 that in the first edition of this work, and subsequently, I placed 

 in a most conspicuous position — namely, at the close of the 

 Introduction — the following words: 'I am convinced that natural 

 selection has been the main but not the exclusive means of 

 modification.' " 



1 See the chapter contributed to the Life and Letters of Charles Darwin, n. p. 195. I do 

 not clearly understand the sense in which Darwin wrote (Autobiography, ibid. i. p. 87) : 

 "It has sometimes been said that the success of the Origin proved 'that the subject was in 

 the air,' or 'that men's minds were prepared for it.' I do not think that this is strictly 

 true, for I occasionally sounded not a few naturalists, and never happened to come across 

 a single one who seemed to doubt about the permanence of species." This experience may 

 perhaps have been an accident due to Darwin's isolation. The literature of the period 

 abounds with indications of "critical expectancy." A most interesting expression of that 

 feeling is given in the charming account of the "Early Days of Darwinism" by Alfred 

 Newton, Macmillan's Magazine, lvii. 1888, p. 241. He tells how in 1858 when spending a 

 dreary summer in Iceland, he and his friend, the ornithologist John Wolley, in default of 

 active occupation, spent their days in discussion. "Both of us taking a keen interest in 

 Natural History, it was but reasonable that a question, which in those days was always 

 coming up wherever two or more naturalists were gathered together, should be continually 

 recurring. That question was, 'What is a species?' and connected therewith was the 

 other question, ' How did a species begin ? '...Now we were of course fairly well acquainted 

 with what had been published on these subjects." He then enumerates some of these 

 publications, mentioning among others T. Vernon Wollaston's Variation of Species — 

 a work which has in my opinion never been adequately appreciated. He proceeds: "Of 

 course we never arrived at anything like a solution of these problems, general or special, 

 but we felt very strongly that a solution ought to be found, and that quickly, if the study 

 of Botany and Zoology was to make any great advance." He then describes how on 

 his return home he received the famous number of the Linnean Journal on a certain 

 evening. "I sat up late that night to read it; and never shall I forget the impression it 

 made upon me. Herein was contained a perfectly simple solution of all the difficulties 

 which had been troubling me for months past.... I went to bed satisfied that a solution 

 had been found." 



2 Origin, 6th edit. (1882), p. 421. 



