en. viii.] ORGANIZATION OF THE SCIENCES. 217 



the advent of creatures sufficiently intelligent to congregate 

 for mutual assistance in permanent family-groups, and by 

 the aid of language to transmit their organized experience 

 from generation to generation, there begin the phenomena of 

 sociology. 



The logical correctness of this threefold division of the 

 sciences is shown by the fact that the several sciences which 

 we have arranged together in each group cohere strongly 

 among themselves, while they do not strongly cohere with 

 the sciences arranged in either of the other groups. The 

 concrete sciences, for example, all agree in having for their 

 subject-matter the study of the aggregates of sensible exist- 

 ences, or of the relations and forces which sensible existences 

 manifest in the state of aggregation. Sidereal Astronomy 

 deals with stellar aggregates scattered, through space just as 

 we find them. " Planetary Astronomy, cutting out of this 

 all-including aggregate that relatively minute part constitut- 

 ing the solar system, deals with this as a whole." Out of 

 the number of aggregates which make up the whole with 

 which planetary astronomy thus deals, Geology selects the one 

 most easily accessible, and studies that one in detail. Again, 

 among the many rearrangements of matter and motion which 

 go on upon the earth's surface, there are found a number of 

 small aggregates which Biology distinguishes as vital, and 

 accordingly selects as constituting its own special subject- 

 matter. Among the many functions which, taken together, 

 make up the life of these organic aggregates, there are sundry 

 " specialized aggregates of functions which adjust the actions 

 3>f organisms to the complex activities surrounding them " ; 

 and these specialized aggregates of functions form the sub- 

 ject-mattu of Psychology. Lastly Sociology "considers each 

 tribe and nation as an aggregate presenting multitudinous 

 phenomena, simultaneous and successive, that are held 

 together as. parts of one combination." So that, from first to 

 last, the object of the concrete sciences is to describe the 



