In 1948, Stanisław Jaśkowski defined a logical system D2 of a discursive sentential calculus. The aim of this paper is to introduce the reader to the basic ideas of the discursive logic and to show, in a historical perspective, its development originating from S. Jáskowski’s two papers [Stud. Soc. Sci. Torunensis 1, 171-172 (1949); Stud. Log. 24, 143-160 (1969; Zbl 0244.02004)]. We intend to ... [Show full abstract] present some problems connected with it and outline the solutions they have received up to the present day.