This work aims at articulating a constructivist or value-dependent conception of legal interpretation and at arguing in defence of its superiority against rival conceptions. Legal interpretation is an activity that implies participating in legal praxis. Thus, it is committed to those ends and values that give meaning to it, or in other words, it is committed to improving such praxis. Accordingly, to answer the question of how to interpret law, we must first answer the question of what makes law valuable. To assess whether a certain interpretation is better or worse than alternatives depends precisely on how it contributes to maximizing those principles making us consider law valuable. Legal argumentation for the purposes of legal interpretation has a necessary moral and political component. Nonetheless, this does not imply disregarding the peculiarities of legal argumentation, particularly the relevance of authoritative elements.