Abstract

In this paper Schlick's use of the term "concept" is analyzed and also secondarily the term "content." An unambiguous and straightforward use of such a basic term as "concept" which is of great importance in Allgemeine Erkenntnislehre in part should determine the value of Schlick's philosophical writing. Concepts are, for Schlick, either pure thought objects or signs. As thought objects, they do not exist at all. I t is shown that as thought objects concepts can be interpreted as sets and that as signs they must be understood as physical designators. Concepts are thought by conceptual functions which Schlick compared with Brentano's intentions. A critical interpretation of conceptual functions is given. Additionally Schlick's theory of defining concepts is analyzed.