Frege on the reference of sentences

Abstract

The aim of this paper is to show that Frege's argument which concluded that the reference of a sentence is its truth-value, presented in 'On Sense and Reference' (1892), can be reconstructed taking into account the problems of the notion of conceptual content presented in the 'Begriffsschrift' (1879) and also other passages from a letter to Russell (1902) and the posthumous 'Logic in Mathematics' (1914). Once the `hybrid' notion of conceptual content was rejected as the semantic value of the expressions of the formal language designed to carry out the logicist project, there was no alternative between truth-values and thoughts. I claim that the reconstructed argument is perfectly sound and convincing.