XXXI.] LIMITS OF SCIENTIFIC METHOD. 763 



furnished with exactly similar germs of life, existed, a 

 race must have grown up there exactly similar to the 

 human race. 



By a different distribution of atoms in the primeval world 

 a different series of living forms on this earth would have 

 been produced. From the same causes acting according to 

 the same laws, the same results will follow ; but from 

 different causes acting according to the same laws, different 

 results will follow. So far as we can see, then, infinitely 

 diverse living creatures might have been created con- 

 sistently with the theory of evolution, and the precise 

 reason why we have a backbone, two hands with opposable 

 thumbs, an erect stature, a complex brain, about 223 bones, 

 and many other peculiarities, is only to be found in the 

 original act of creation. I do not, any less than Paley, 

 believe that the eye of man manifests design. I believe 

 that the eye was gradually developed, and we can in fact 

 trace its gradual development from the first germ of a nerve 

 affected by light-rays in some simple zoophyte. In propor- 

 tion as the eye became a more accurate instrument of 

 vision, it enabled its possessor the better to escape destruc- 

 tion, but the ultimate result must have been contained in 

 the aggregate of the causes, and these causes, as far as we 

 can see, were subject to the arbitrary choice of the Creator. 



Although Agassiz was clearly wrong in holding that 

 every species of living creature appeared on earth by the 

 immediate intervention of the Creator, which would amount 

 to saying that no laws of connection between forms are 

 discoverable, yet he seems to be right in asserting that 

 living forms are distinct from those produced by purely 

 physical causes. " The products of what are commonly 

 called physical agents," he says,^ " are everywhere the 

 same {i.e. upon the whole surface of the earth), and have 

 always been the same {i.e. during all geological periods) ; 

 while organised beings are everywhere different and have 

 dilfered in all ages. iJetween two such series of phenomena 

 there can be no causal or genetic connection." Living forms 

 as we now regard them are essentially variable, but from 

 constant mechanical causes constant effects would ensue. 

 If vegetable cells are formed on geometrical principles 



' Agassiz, Essay on Classiji ation, p. 75. 



