According to constitutivism, we can justify the authority of aims and norms on the ground that they are inescapable. Constitutivist views divide between ambitious and modest ones. According to ambitious constitutivism, the inescapability of aims grounds their unconditional authority, whereas according to modest constitutivism, the inescapability of aims only grounds their conditional authority. Either way, both forms of constitutivism share the assumption that inescapability grounds authority, which in turn presupposes that at the foundation of normativity we find aims and norms (...) that can be evaluated as having or lacking authority. In this paper I shall defend a form of constitutivism that rejects this assumption. According to this view, which I shall call Hinge Constitutivism, at the foundation of epistemic normativity we find an aim, the truth-aim, that is altogether beyond the evaluation in terms of the ordinary notion of authority. Moreover, I shall argue that to aim at truth is a condition of possibility for justifying the authority of any other aims or norms. In this sense, to aim at truth is a hinge of deliberation. (shrink)