The article examines theoretical and methodological approaches to studying social future. Most of such studies in sociology are represented by descriptions and explanations of social phenomena observed "here and now". However, object and subject in sociology are diachronic: the object of sociology is the present, but its subject (explicit or latent) is the future. Three approaches characterized by varying relationship between the present as an obvious object and the future as not always thoroughly recognized subject can be traced in the history of theoretical sociology. H. Marcuse's critical theory of society is analyzed as a successful actualization of dialectical approach deriving the model of social future from negative trends of the present. Applying dialectical approach to analysis of curent forms of capitalism and movements for freedom and equality allows to reveal emergence of new forms of social control and inequality.