110 Herhert Spencer's Syntlietic Philosophy. 



of molten lead or sulphur, and the impossibility of keeping 

 a body of water free from currents. Tlie more heterogene- 

 ous a body becomes, the more rapid the multiplication of 

 effects. Every event which involves the decomposition of 

 force into several forces produces greater complication and 

 increased heterogeneity ; and, when this process of differen- 

 tiation combines with the process of integration to make 

 the change from the homogeneous to the heterogeneous at 

 the same time as that from the indefinite to the definite, we 

 have compound evolution. Mere increase of heterogeneity 

 and multiformity of parts does not constitute progress. A 

 cancer introduces into an organism changes that make it 

 more heterogeneous, yet it may cause death. The anarchy 

 resulting from a revolution makes a state more heterogene- 

 ous, yet it may be the precursor of its dissolution. The law 

 of passage from the homogeneous to the heterogeneous is a 

 law of progress, but not the law of progress. The primary 

 law of progress (or evolution, which in his later works 

 Spencer substitutes for the word " progress ") is the inte- 

 gration of matter and the concomitant dissipation of mo- 

 tion, which is alike exhibited in the crystallization of carbon 

 into a diamond and the growth of an animal from a germ ; 

 but when, as in the field of biology, there is with continual 

 integration of matter increasing heterogeneity of form, 

 progress is possible only when there is also increasing co- 

 herence, detinitencss, and mutual dependence of parts and 

 a subordination of the various parts and manifold functions 

 to the movements of the whole structure. Cancers produce 

 differentiation ; but, as they can not be integrated in har- 

 mony with the rest of the body, they result not in progress 

 but in death. Thus it is seen that evolution is a double 

 process — a movement toward unity as well as diversity. In- 

 tegration, the primary process, under certain conditions the 

 most completely realized by organic bodies, is accompanied 

 by a complementary process from indefinite, incoherent 

 homogeneity to definite coherent heterogeneity. Variety 

 increases with the unity it accomplishes. The evolution of 

 an animal from an egg or a tree from a seed occurs by the 

 integration of various elements into a complex structure, in 

 which at the same time go on continual differentiations and 

 local integrations, making the whole a compact aggregate 

 that presents great iieterogeneity in itself and at the same 

 time a wide differentiation from all other aggregates. 



9. The field of this compound evolution is among bodies 



