444 POPULAR SCIENCE MONTHLY. 



convinced him that he had fallen into error that the transforma- 

 tion of the homogeneous into the heterogeneous does not sum up 

 the whole of evolution, but only the most conspicuous part of the 

 secondary redistribution of matter and motion constituting it. 

 Many changes in the direction of increasing heterogeneity e. g., 

 the rise of a cancer in the individual organism, or of a revolution 

 in the state obviously tend not to evolution, but to dissolution. 

 When, then, does increase in complexity mean evolution ? The 

 answer to this question, found in a return to the principle of in- 

 tegration, is, when increase of complexity is accompanied by 

 more and more complete interdependence among the specialized 

 parts by increase in organic unification. Evolution, therefore, 

 may be roughly defined as change toward multiformity in unity, 

 brought about by the rise of unlikenesses (differentiation) and the 

 concentration of the unlike parts, through mutual dependence, 

 into an organized whole (integration) ; or, to phrase the doctrine 

 philosophically in Mr. Spencer's world-famous formula, as "an 

 integration of matter and concomitant dissipation of motion ; 

 during which the matter passes from an indefinite incoherent 

 homogeneity to a definite coherent heterogeneity, and during 

 which the retained motion undergoes a parallel transformation." 



But with the formulation of this all-pervading process, we 

 reach only the starting-point of a fresh investigation. Philoso- 

 phy the complete unification of knowledge demands the re- 

 statement of the law of evolution in deductive form. Such being 

 the transformations manifested by all classes of concrete phe- 

 nomena, we ask. Why this continuous metamorphosis ? We must 

 seek the rationale of the universal changes inductively set forth, 

 must undertake to interpret them as necessary consequences of 

 some deeper law. 



Incidentally we may notice here the firm, logical consistency 

 of the Spencerian system. While it presents us with a history of 

 the knowable universe in empirical generalizations, it also affil- 

 iates these all-embracing generalizations upon ultimate principles, 

 derives them from its final dictum, and thus furnishes a rational 

 history of the knowable universe as well. Undertaking, there- 

 fore, the task of presenting the phenomena of evolution in syn- 

 thetic order, Mr. Spencer arrives at the law of the instability of 

 any finite homogeneous aggregate owing to the unequal exposure 

 of its parts to incident forces, and proceeds to show, first, that 

 " every mass, or part of a mass, on which a force falls subdivides 

 and differentiates that force, which thereupon proceeds to work a 

 variety of changes "; and, secondly, that the process of segrega- 

 tion, " tending ever to separate unlike units and to bring together 

 like units," serves constantly " to sharpen or make definite differ- 

 entiations otherwise caused." Finally, these laws the instability 



