Schlick's personal relations with the author of the Tractatus began in 1927. From the outset Schlick was greatly impressed by Wittgenstein and deeply regretted his having given up work in philosophy. In this connection, I remember a party sometime after Schlick had returned from England.1 The conversation turned to some philospher or scientist who had stopped working and someone brought up Wittgenstein. "There is a great difference, though," said Schlick. "Mr. (whoever it was) ceased working because of fatigue, whereas Wittgenstein has given up work because of ressentiment." I remember Schlick using the French word, which incidentally has no precise German counterpart and, in a way, is slightly stronger than the English "resentment." ("Souvenir d"une injure, désir de s"en ve-nger," explains Larousse and adds the example "conserver le vif ressentiment d"une offense.") At this point, the conversation unfortunately was interrupted by someone's joining the group and was not resumed despite the questions it raised in my mind. Then and later various signs seemed to me to point to Wittgenstein's particular resentment against mathematicians. Schlick's awareness of this fact may have been one of the reasons why, in 1927, he introduced Carnap, Feigl, and Waismann (who was by then definitely a philosopher rather than a mathematician) to Wittgenstein while keeping mathematicians away from him.