As you all know, the Vienna Circle called the international gatherings which it organized, as its influence extended beyond its home city, "Congresses for the Unity of Science" ("Kongresse für Einheitswissenschaft")..The second of these (so-called) took place in Copenhagen in June 1936, a little more than 50 years ago. I say 'so-called", because it really was the fifth, meetings (called "Tagungen für Erkenntnislehre der exakten Wissenschaften") having been held in Prague 1929 and in Königsberg 1930, and a "Vorkonferenz" held in Prague 1934. The latter was attended by a number of Poles, as was the case two years later in Copenhagen. There is no doubt that already in the middle thirties the logical-positivist movement and the Lvov-Warsaw school felt a strong affinity to each other. I remember that on the excursion to Elsinore arranged on June 23rd in connection with the Copenhagen congress I found myself in a bus surrounded by people talking to each other in a language completely incomprehensible to me as, to my great regret, it still is today.