According to the standard characterization of logic in Frege's writings, the word "true" indicates the essence of logic, as the word "good" indicates the essence of ethics and the word "beautiful" the essence of aesthetics. In a posthumous writing from 1915, however, Frege says that it is the assertoric force, and not the word "true", which indicates the essence of logic properly. Prima facie, this correction is in conflict with Frege's criticism of the psychologist conception of logic. For according to this criticism, logic is not the science of the laws of "being taken as true", but the science of the laws of "being true", while the assertoric force expresses being taken as true. In previous writings, I tried to resolve this conflict by a reconstruction of Frege's conception of truth that is based on his thesis that truth is expressed in natural language by the "form of the assertoric sentence". The goal of this paper is to defend this interpretation against the objections recently made by Marco Ruffino.
Frege; Essence of logic; Truth; Assertoric force