198 Professor 71 H. Huxley, [Feb. 10, 



nature (even if we consider the physical world as a mere mechanism) 

 must tend to cherish those varieties which are better fitted to work 

 harmoniously with tlie conditions she offers, and to destroy the rest. 



There seems to be no doubt then, that modifications equivalent in 

 extent to the four breeds of pigeons, might be developed from a 

 species by natural causes ; and therefore, if it can be shown that these 

 breeds liave all the characters which are ever found in species, Mr. 

 Darwin's case would be complete. However, there is as yet no proof 

 that, by selection, modifications having the physiological character of 

 species {i.e. whose offspring are incapable of propagation, inter se) 

 have ever been produced from a common stock. 



No doubt the numerous indirect arguments brought forward by 

 Mr. Darwin to weaken the force of this objection are of great weight ; 

 no doubt it cannot be proved that all species give rise to hybrids 

 infertile, inter se ; no doubt (so far as the speaker's private convic- 

 tion went), a well conducted series of experiments very probably 

 would yield us derivatives from a common stock, whose offspring should 

 be infertile, inter se : but we must deal with facts as they stand ; and 

 at present it must be admitted that Mr. Darwin's theory does not 

 account for all the phenomena exhibited by species ; and so far, falls 

 short of being a satisfactory theory. 



Nevertheless the speaker expressed his sense of the extremely high 

 value to be attached to Mr. Darwin's hypothesis ; and, avowing his own 

 conviction that the following it out must ultimately lead us to the 

 detection of the laws which have governed the origin of species, he 

 concluded his discourse in the following words, which he wishes to be 

 added in full to the very brief preceding account of his view of Mr. 

 Darwin's argument : — 



" I have endeavoured to lay before you what, as I fancy, are the turn- 

 ing points of a great controversy ; to render obvious the mode in which 

 the vast problem of the origin of species must be dealt with ; and so 

 far as purely scientific considerations go, I have nothing more to say. 

 But let me beg you still to listen to a last word respecting the un- 

 scientific objections which I constantly hear brought forward, on the 

 part of the general public, against such doctrines as those we have 

 been discussing. For this is a matter upon which it is of the utmost 

 importance that men of science and the public should come to an under- 

 standing. I have heard it said, that it is presumptuous for us to attempt 

 to inquire into such matters as these ; that they are problems beyond 

 the reach of the human understanding. Do you remember what was the 

 reply of the old philosopher to those who demonstrated to him so 

 clearly the impossibility of motion ? * Solvitur ambulando,' said he, 

 and got up and walked. And so I doubt not that one of these days 

 either Mr. Darwin's hypothesis, or some other, will get up and walk, 

 and that vigorously ; and so save us the trouble of any further dis- 

 cussion of this objection. 



" Another, and unfortunately a large class of persons take fright 

 at the logical consequences of such a doctrine as that put forth by 



