During the years 1945 - 1950 he took over the Department of Classical Antiquity, then the Department of Comparative Literature at the Catholic University of Lublin (KUL). He became a regular member of Warszawskiego Towarzystwa Naukowego (Warsaw Association of Sciences), worked with publications such as the "Universal Weekly", "Meander", "Creation", and renewed his activities as chairman of the Polish PEN Club. In 1948 he organized a World Congress of Intellectuals in Wrocław, after which he went back to live in Warsaw. 