Frege on Knowledge, Science, and Logic: Truth qua the Reference of True Sentences

According to an arguable reading of truth in Frege, he takes truth to be an object, specifically, the truth-value True qua the reference of true sentences. This paper addresses a challenge that should be met by this objectualist reading of Frege’s conception of truth. Frege takes it for granted that all sciences aim at truth. Among these sciences, however, only logic deserves to be called ‘the science of truth’. First, if truth is an object for Frege, he should accept that all sciences aim at a single object. How can there be a single object all sciences aim at? Also, he should accept that logic is the science of a single object. In what sense can logic, and only logic, be the science of a single object? For Frege, propositional knowledge is reduced to non-propositional knowledge of the identity of the True. Thus, acquiring new propositional knowledge expands our knowledge of the identity of the True, which in turn expands our knowledge of the True. Sciences are intellectual activities by which we aim to pile up propositional knowledge. So, the aim of all sciences is to expand our knowledge of the True. Logic is the science of the True because it examines how far we can expand our knowledge of the True when truth-values are the only objects known to us.