The chapter presents the main achievements of the Poznań School of Methodology against the background of the postwar history of Polish philosophy. In its first part, the history of Polish philosophy in the twentieth century is outlined. In the second part, the institutional history of the Poznań School is sketched, and its main sources of inspiration and determinants of the School’s research program are identified. In the third part the main scientific achievements of Jerzy Kmita, Leszek Nowak and Jerzy Topolski—three major advocates of the School—are presented.