The article analyzes the connection and correlation of social philosophy and ideology. There are a large number of different, sometimes contradictory, and even mutually exclusive, definitions of ideology in the modern science. The author suggests that in order to understand this phenomenon of social life, the most promising is the functional approach. This is due to the fact that ideology is capable of realizing itself in a wide variety of forms. Moreover, it often avoids speaking on its behalf, posing as other spiritual practices (art, science, etc.), and therefore remains unnoticed, invisible social force. At the same time, in the modern world with the development and improvement of the mass communication media, it is becoming more and more “elusive”. In this case, the common goal for these various manifestations of ideology will not be their form, structure or content, but the very goal that they pursue. The fundamental system-forming function of ideology is the function of legitimizing the social-economic and social-political system and/or programs for changing it. As a social philosophy as a whole, ideology cognizes and understands the surrounding reality, but does so only to the extent that it helps achieving her own political goals.