Truth and knowability: on the principles C and K of Michael Dummett

Source abstract

Abstract There is an ambiguity in the term ‘assertion’: you may use it either generally for a claim, a knowledge claim, or specifically for an affirmation, that is, for a claim of the form ‘A is true’, where A is a proposition. In this talk, I shall use it consistently in the first of these two senses. Also, I shall use the terms ‘assertion’ and ‘judgement’ synonymously. At the bottom of my list is the notion of truth as one pole of the distinction between appearance and reality: it is so to speak the high notion of truth, often capitalized, although I have put it at the bottom. At the top is the notion of truth of closed formulas, or sentences, which is the lowest notion in the sense that it is a purely mathematical notion, determined by Tarski’s well-known recursive definition, and I shall not be concerned with that either, but remain in the middle region, dealing exclusively with the notion of truth of a proposition and the notion of truth of an assertion, or judgement.