Mentality: a philosophical nvestigation

In the article there has been carried out the retrospective analysis of understanding mentality. The author accentuates the vision of mentality as the expression of the most essential relations of actuality. The term is interpreted from ontological positions. Ontological basics of mentality are given through its functioning as a priori structure which has level character. There has been formulated the definition of mentality. There have been outlined the subjects of mentality. There is proposed the vision of mentality as a philosophical category. There is positioned its use while researching the patterns of culture development with internal processes of self-organisation and external constructive impacts. Mentality is interpreted as a principle of thinking which means the unity of biological, psychological and cultural basics in socio-cultural subjects. There is proposed the idea of using a category "mentality" as a principle of thinking in different sciences such as history, philosophical anthropology, psychology etc.