AND ITS SELF-CONSERVATION. 49 



force, that is, attraction. And in tracing the dialectic of 

 repulsion we have seen how, in its own activity as repul- 

 sion, it necessarily develops into its own opposite, that is, 

 into attraction. Thus it would seem that either of these 

 two modes of force is wholly unthinkable apart from the 

 other. They appear to be but different aspects of one and 

 the same force or energy. And this becomes only the 

 more evident as we trace out the dialectic of attraction 

 from the assumption that it is an independent mode of 

 force. 



1. ATTRACTION. 



Throughout the scientific world attraction is con- 

 stantly referred to as if it were regarded as pre-emi- 

 nently the one universal mode of force. And in some of 

 its phases it does seem to act quite independently. It will 

 be well, then, to examine it in its seeming independence. 



Objects of sense-perception present definite boundaries, 

 and we have seen that they offer resistance to any force 

 tending to compress them. But they also offer resistance 

 to efforts made to change their shape, or to divide them. 

 Evidently then the particles hold fast upon one another 

 attract each other. 



Thus at once it comes to light that the resistance which 

 a body offers to pressure is due, not merely to the repul- 

 sion of its particles for one another, but also quite as much 

 to the relation of attraction between them holding them in 

 fixed relative positions. So that the impenetrability of 

 bodies proves to be a repulsion, which in large measure 

 has its truth in attraction. If I press a piece of moist 

 clay between my fingers it yields, not because of the lack 

 of repulsion between the particles in the immediate line 



