Abstract

The aim of this paper is to point out some interesting features of Moritz Schlick’s thought regarding both his refusal of Metaphysics and his view of the relationship between Realism and Positivism. In particular, the author stresses the importance of Schlick’s early attempts to define the concept of truth as well as to formulate a kind of pre-linguistic verificationism. Unpublished letters and manuscripts have been considered in order to give a more precise picture of Schlick’s intellectual development, from the beginning of his academic career up to the unknown letters documenting his discussion with Max Planck about Realism in the early Thirties.