CONCLUSION 
263 
view thought of sociology in terms of a general social psy- 
chology (Le Bon, Sighele), some in terms of a science of 
social interactions (Gumplowicz, Giddings), some in terms 
of a philosophy of history (Barth), some in terms of a social 
philosophy (Stein), and some in terms of a philosophy of 
the social sciences (Ratzenhofer, Small). Nor was there 
any more agreement regarding the fundamental category 
of this study of sociology; but here, at least, the funda- 
mental differences were not quite so great as the discrepan- 
cies in terminology would seem to indicate. The essentially 
social category was, for de Roberty, sociality; for de Greef 
and Fouillée, contract; for Gumplowicz, conflict; for Tarde. 
imitation; for Durkheim, coercion; for Giddings, con- 
sciousness of kind; for Ratzenhofer and Small, association; 
and for Stuckenberg, sociation. These different terms con- 
note very different concepts, but they indicate also the 
gradual realization that the aim should be not so much a 
philosophy of society as a whole as a study of the specific 
phenomena of social interaction. 
In this period of confusion appeared the work of Georg 
Simmel. The fundamental points in his theory were for- 
mulated well before the end of the century, and he there- 
fore definitely belongs to the nineties. His great contribu- 
tion is a methodological foundation for a science of soci- 
ology distinct and separate from social psychology, the 
social sciences, social philosophy, and the philosophy of 
history. He defined the subject-matter of that science as 
the forms of socialization, that is, as the purely social as- 
pect of socialization or association as such. The value of 
his work does not lie in its startling originality, but in the 
careful methodological justification of its essential con- 
cepts. He owed a great deal to his predecessors, perhaps 
more in particular to Gumplowicz, but his philosophic