32 THE ORIGIN OF SPECIES n 



and matter and force are the two names of the 

 one artist who fashions the living as well as the 

 lifeless. Hence living bodies should obey the 

 same great laws as other matter nor, throughout 

 Nature, is there a law of wider application than 

 this, that a body impelled by two forces takes the 

 direction of their resultant. But living bodies 

 may be regarded as nothing but extremely complex 

 bundles of forces held in a mass of matter, as the 

 complex forces of a magnet are held in the steel 

 by its coercive force ; and, since the differences 

 of sex are comparatively slight, or, in other words, 

 the sum of the forces in each has a very similar 

 tendency, their resultant, the offspring, may reason- 

 ably be expected to deviate but little from a course 

 parallel to either, or to both. 



Represent the reason of the law to ourselves by 

 what physical metaphor or analogy we will, how- 

 ever, the great matter is to apprehend its existence 

 and the importance of the consequences deducible 

 from it. For things which are like to the same 

 are like to one another ; and if, in a great series of 

 generations, every offspring is like its parent, it 

 follows that all the offspring and all the parents 

 must be like one another; and that, given an 

 original parental stock, with the opportunity of 

 undisturbed multiplication, the law in question 

 necessitates the production, in course of time, of 

 an indefinitely large group, the whole of the mem- 

 bers of which are at once very similar and are blood 



