The article gives the substantiation attitude that out-of-school and additional education has to interact and cooperate with school education closely. The author presented theoretical bases of formation and development of out-of-school and additional education in the pre-revolutionary period where lifting of humanistic thought was observed, moral reference points were overestimated, the importance of the personality was realized. Features of out-of-school education in Bashkortostan at the end of XIX - the beginning of XX century are considered, objective factors of its development are shown. Concepts of teachers scientists on a problem of out-of-school education, in particular, concerning a library science, national readings, schools for adults, museums and another are analysed and generalized.