Abstract: The object of this research is the processes of de-ideologizaton and re-ideologizaton. The subject is the finalist theories, namely the theories of the “end of history and “and of ideology”. The goal of this work consists in demonstration of peculiarities of the concept of ideology of the last quarter of the XX century, determination and revelation of the processes of de-ideologizaton and re-ideologizaiton, as well as analysis of the views of separate representatives of the indicated directions respectively. Special attention is given to the works of Daniel Bell, Seymour Lipset, Eugen Lemberg, Jakob Barion, and Francis Fukuyama. The main scientific methodological approaches of this work are the comparative and system. Comparative method was implemented for pursuing correlation between the theories and concepts of ideology of the last quarter of the XX century. For analysis of de-ideologizaton and re-ideologizaton as a single process associated with the relevant for that time historical events, the author applied the system approach. Theoretical importance of this research is defined by the more profound comprehension of the origins and specificity of the processes of de-ideologizaton and re-ideologizaton upon the formation of the concepts of ideology. The author concludes that the theories of the “end of history” represent a vivid example of the ideological confrontation of the XX century, rather than rejection of the ideology as such; the objective scientific knowledge called by the de-ideologizators to replace the ideology, became an instrument (especially sociology) in political struggle.