  The Lvov-Warsaw School (LWS) was the most important movement in the history of Polish philosophy. It was established by Kazimierz Twardowski at the end of the 19th century in Lvov (i.e., the Ukrainian city of Lviv, which at that time was part of the Austro-Hungarian Empire). The LWS flourished in the years 1918–1939. Kazimierz Ajdukiewicz, Tadeusz Kotarbiński, Stanisław Leśniewski, Jan Łukasiewicz and Alfred Tarski are its most famous members. It was an analytical school similar to the Vienna Circle in many respects. On the other hand, the attitude of the LWS toward traditional philosophy was much more positive than that of logical empiricism. Although logic became the most important field in the activities of the LWS, its members were active in all spheres of philosophy. World War II and political changes in Poland after 1945 caused the end of the LWS as an organized philosophical enterprise. One can consider it to have later been continued individually by its representatives.