In this paper, I present different ways in which transcendental argumentation has been used in contemporary debates in moral philosophy to justify the normative authority of morality. My aim is to defend strong “retorsive” transcendental argumentation as a way to ground a sort of critical realism in metaethics, comparing transcendental arguments proposed by Karl-Otto Apel, Christine Korsgaard and Alan Gewirth – which are sometimes referred to as “constitutivist” arguments. In particular, I endorse an argumentative strategy that considers the merits of (...) the respective positions while overcoming the limits of each. Such a strategy aims at grounding transcendentally the metaphysical fact of human value, making explicit the ontological implications of transcendental argumentation, and showing that a justification of fundamental values alone can ultimately make it possible to ground basic moral principles. (shrink)