THE LAW OF HEREDITY 5 



elements of the world ; let us represent each by 

 a thread of peculiar colour, itself formed by a col- 

 lection of finer threads ; a superior force — God, 

 Nature, Chance, it matters not what — is ever 

 weaving, knotting, and unknotting these, and 

 transforming them into various patterns. To the 

 ordinary mind there is nothing besides these knots 

 and these patterns ; for it these are the only 

 reality ; beyond them it knows nothing, suspects 

 nothing. But the man of science sets to work ; 

 he unties the knots, unravels the patterns, and 

 shows that all the reality is in the threads. Then 

 the antagonism between fact and law disappears; 

 facts are but a synthesis of laws, laws an analysis 

 of facts." ^ If, now, we unravel the fabric of 

 human life, shall we find the threads of heredity 

 in its warp .-' Without doubt we shall. There 

 are easily verified facts in abundance which 

 make it evident that heredity is a veritable law, 

 holding true at once in the physical, the mental, 

 and the moral spheres. 



(i) By the act of generation all that distin- 

 guishes species as species is invariably transmit- 

 ted. " Like produces like." Monkeys always 

 give birth to monkeys ; birds to birds ; fish are 

 the offspring of fish ; and human beings inva- 



1 Heredity, Ribot, p. 136. 



