Abstract
Künne outlines Bolzano’s attempt to give a definition of the concept of truth and asks whether Frege succeeded in showing that all such endeavours are doomed to failure. Bolzano and Frege are agreed that the schema ‘That p is true if, and only if, p’ captures an important feature of the concept of truth, and in different ways both went beyond this observation: Frege maintained that the two halves of such biconditionals express the same proposition, and Bolzano supplemented the equivalence schema with ‘If it is true that p then it is true because p’. Künne locates this true-because principle in Bolzano’s general theory of grounding and explores whether Frege’s Identity Thesis can be refuted by appealing to it.