354 COSMIC MILOSOrilY. [it. ti. 



accurately made pair of scales, in the equal impossibility of 



keeping a tank of water free from currents, in the rusting of 

 iron, and in the uneven cooling of a heated metal, is exem- 

 plified the principle that the state of homogeneity is an 

 unstable state. Universally the tendency of things, amid 

 the conflict of unlike forces, is toward heterogeneity. 



Coincident with the differentiation of aggregates, there is 

 a differentiation of the incident forces. AVhen a moving 

 hody is broken up by collision, its original momentum is 

 severed into a group of momenta, which differ both in amount 

 and in direction. The ray of solar light which falls upon 

 the foliage of a tree and upon the wall of the brick building 

 behind it is separated by reflection into red and green 

 rays, in which the undulations differ both in height and in 

 breadth. Each portion of the differentiated force must in its 

 turn enter as a factor into new differentiations. The more 

 heterogeneous an aggregate becomes the more rapidly must 

 differentiation go on ; because each of its component units 

 may be considered as a whole, bearing relations to the other 

 units similar to those which the aggregate bears to other 

 nggregates ; and thus the differentiation of the whole must 

 be followed by the differentiation of the parts. There must 

 thus be a multiplication of effects as heterogeneity increases ; 

 because, with increasing heterogeneity, the forces which 

 bodies and parts of bodies mutually exert upon each other 

 must become ever more varied and complex in their amounts 

 and directions. 



We may see, therefore, that differentiation is a necessary 

 consequence of the fundamental relations of matter and 

 motion. And the same is true of that secondary integration 

 or union of like units, which serves to render differentiation 

 more conspicuous by substituting a demarcated grouping for 

 a vague one. Considering what happens when a handful of 

 pounded sugar, scattered before the breeze, falls here and 

 there according to the respective sizes of the fragments, — we 

 perceive that the units which descend in company are those 



