In this article, the authors try to redefine G. Tarde's and E. Durkheim's contribution to social theory. Drawing on comparative analysis of the theories of social change, the differences between E. Durkheim's and G. Tarde's sociological projects are shown. These differences cannot be reduced to the opposition between psychologism and sociologism or sociological nominalism and realism. They are considered as a result of essentially different understanding of the nature of social fact. The authors make an assumption that G. Tarde's sociology of associations project, which is underestimated in Russian sociology, is an alternative to E. Durkheim's sociology.