Abstract

In March 1930, Alfred Tarski visited Vienna and delivered few lectures which presented the achievements of the logical branch of the Lvov-Warsaw School. Rudolf Carnap was one of the most careful listeners of these lectures. The same year, in November, Carnap, invited by the Warsaw Philosophical Society, visited Warsaw where he gave three lectures. This was an opportunity for him to meet such members the Lvov-Warsaw School as Jan Łukasiewicz, Stanisław Leśniewski, Tadeusz Kotarbiński, and others. Many years later, Carnap reminisced that he left Warsaw “grateful for many stimulating suggestions and the fruitful exchange of ideas”.In the paper, I reconstruct the details of Carnap’s visit in Warsaw based on Carnap’s diaries, reports published in the Polish Journal Ruch Filozoficzny [Philosophical Movement] and some correspondence. I also discuss some problems presented by Carnap in Warsaw lectures and compare his views to the positons of members of the Lvov-Warsaw School. These problems are: the foundations of psychology, the status of metaphysical sentences, and the character of reasoning.