en. xviu.] THE EVOLUTION OF SOCIETY. 215 



Alexander, the spread of Eoman dominion, the Arahian con- 

 quests, the Crusades, and the voyages of Columbus, Magellan, 

 and De Gama. The invention of printing, increasing the 

 rapidity and the frequency with which the thoughts of 

 various minds are brought into contact, offers another illus- 

 tration ; and in a similar way is to be explained the civilizing 

 agency of railroads and telegraphs. 



Comparing these deductions with the historical survey of 

 ethical development above taken, we arrive at a set oL 

 mutually harmonious conclusions. We see that the process 

 of intellectual and moral adaptation which constitutes social 

 progress is determined by the steadily increasing hetero- 

 geneity of the social environment. And we see that this 

 increased heterogeneity of the environment is caused by the 

 integration or growing interdependence of communities that 

 were originally isolated. We have now to examine this 

 process of integration somewhat more in detail. By insti- 

 tuting a novel comparison between the processes of organic 

 and of social life, we shall be led directly to the special law 

 of progress for which we are seeking. 



Observe first that the living beings which are lowest, or 

 next to the lowest, in the scale of organization — as, lor 

 example, the protococcus and the amoeba — are nothing but 

 simple cells. It has been shown, by Mr. Spencer, that 

 progress in morphological composition, both in the animal 

 and in the vegetable kingdoms, consists primarily in Hie 

 union of these simple cells into aggregates of higher and 

 higher orders of complexity. Now in the study of social 

 evolution we are met by precisely similar phenomena. Let 

 us consider what is implied by the conclusions at which 

 Sir Henry Maine has arrived, in his profound treatise on 

 " Ancient Law," by an elaborate inquiry into early ideas 

 of property, contract, and testamentary succession, and into 

 primitive criminal legislation. " Society in ancient times," 

 Bays Sir Henry Maine, " was not what it is assumed to be 



