352 LIFE OF PROFESSOR HUXLEY chap, xxiv 



If (he said) the expectation raised by the splints of the 

 horses that, in some ancestor of the horses, these splints would 

 be found to be complete digits, has been verified, we are fur- 

 nished with very strong reasons for looking for a no less com- 

 plete verification of the expectation that the three-toed Plagio- 

 lophus-Uke " avus " of the horse must have been a five-toed 

 " atavus " at some early period. 



Six years afterwards, this forecast of paleontological re- 

 search was to be fulfilled, but at the expense of the European 

 ancestry of the horse. A series of ancestors, similar to these 

 European fossils, but still more equine, and extending in 

 unbroken order much farther back in geological time, was 

 discovered in America. His use of this in his New York 

 lectures as demonstrative evidence of evolution, and the im- 

 mediate fulfilment of a further prophecy of his will be told 

 in due course. 



His address to the Cambridge Y.M.C.A., " A Commen- 

 tary on Descartes' ' Discourse touching the method of using 

 reason rightly, and of seeking scientific truth,' " was deliv- 

 ered on March 24. This was an attempt to give this dis- 

 tinctively Christian audience some vision of the world of 

 science and philosophy, which is neither Christian nor Un- 

 christian, but Extra-christian, and to show " by what meth- 

 ods the dwellers therein try to distinguish truth from false- 

 hood, in regard to some of the deepest and most difficult 

 problems that beset humanity, " in order to be clear about 

 the actions, and to walk sure-footedly in this life," as Des- 

 cartes says. For Descartes had laid the foundation of his 

 own guiding principle of " active scepticism, which strives 

 to conquer itself." 



Here again, as in the Physical Basis of Life, but with 

 more detail, he explains how far materialism is legitimate, 

 is, in fact, a sort of shorthand idealism. This essay, too, 

 contains the often-quoted passage, apropos of the " intro- 

 duction of Calvinism into science." 



I protest that if some great Power would agree to make me 

 always think what is true and do what is right, on condition of 

 being turned into a sort of clock and wound up every morning 

 before I got out of bed, I should instantly close with the offer. 



