MOZLEY ON EVOLUTION. 771 



pressed) ; in the aggregate of organisms throughout geologic time ; in the mind ; 

 in society ; in all products of social activity. 



" ' 6. The process of integration, acting locally as well as generally, combines 

 with the process of differentiation to render this change not simply from homo- 

 geneity to heterogeneity, but from an indefinite homogeneity to a definite heter- 

 ogeneity; and this trait of increasing definiteness, which accompanies the trait 

 of increasing heterogeneity, is, like it, exhibited in the totality of things and in 

 all its divisions and subdivisions down to the minutest. 



"'7. Along with this redistribution of the matter composing any evolving 

 aggregate there goes on a redistribution of the retained motion of its compo- 

 nents in relation to one another ; this also becomes, step by step, more definitely 

 heterogeneous. 



u 8. In the absence of a homogeneity that is infinite and absolute, that re- 

 distribution, of which evolution is one phase, is inevitable. The causes which 

 necessitate it are these : 



" ' 9. The instability of the homogeneous, which is consequent upon the 

 different exposures of the different parts of any limited aggregate to incident 

 forces. The transformations hence resulting are complicated by 



" ' 10. The multiplication of effects. Every mass and part of a mass on which 

 a force falls subdivides and differentiates that force, which thereupon proceeds 

 to work a variety of changes ; and each of these becomes the parent of similarly- 

 multiplying changes; the multiplication of them becoming greater in proportion 

 as the aggregate becomes more heterogeneous. And these two causes of increas- 

 ing differentiations are furthered by 



"'11. Segregation, which is a process tending ever to separate unlike units 

 and to bring together like units so serving continually to sharpen, or make 

 definite, differentiations otherwise caused. 



" ' 12. Equilibration is the final result of these transformations which an evolv- 

 ing aggregate undergoes. The changes go on until there is reached an equilibri- 

 um between the forces which all parts of the aggregate are exposed to, and the 

 forces these parts oppose to them. Equilibration may pass through a transition 

 stage of balanced motions (as in a planetary system), or of balanced functions 

 (as in a living body), on the way to ultimate equilibrium ; but the state of rest 

 in inorganic bodies, or death in organic bodies, is the necessary limit of the 

 changes constituting evolution. 



" ' 13. Dissolution is the counter-change which sooner or later every evolved 

 aggregate undergoes. Remaining exposed to surrounding forces that are un- 

 equilibrated, each aggregate is ever liable to be dissipated by the increase, grad- 

 ual or sudden, of its contained motion ; and its dissipation, quickly undergone 

 by bodies lately animate and slowly undergone by inanimate masses, remains to 

 be undergone at an indefinitely remote period by each planetary and stellar mass, 

 which since an indefinitely distant period in the past has been slowly evolving; 

 the cycle of its transformations being thus completed. 



"Ui. This rhythm of evolution and dissolution, completing itself during short 

 periods in small aggregates, and in the vast aggregates distributed through space 

 completing itself in periods which are immeasurable by human thought, is, so 

 far as we can see, universal and eternal each alternating phase of the process 

 predominating now in this region of space and now in that, as local conditions 

 determine. 



" ' 15. All these phenomena, from their great features down to their minutest 

 details, are necessary results of the persistence of force, under its forms of mat- 



