This is the draft of a new chapter for the Revised Second Edition of my Interpretation and Legal Theory (forthcoming by Hart Publishing). It focuses on some of the unique moral and interpretative concerns of constitutional interpretation. The interpretation of a written constitution typically involves the power of the judiciary to determine issues of profound moral and political importance, on the basis of very limited textual guidance, resulting in decisions that may last for decades, and are practically almost impossible to change by regular democratic processes. This tension between the scope of the judicial power and the relative paucity of constraints informs the main concerns of constitutional interpretation. Accordingly, this essay concentrates on two main questions: The question of the moral legitimacy of a constitutional regime, and the question of how constitutional interpretation should be carried out. It is one of the main arguments of this essay that the answers to these two questions are closely related. The first part of the essay raises some concerns about the moral legitimacy of written constitutions and of judicial review. The second part strives to elaborate on certain methods of constitutional interpretation in the light of these moral concerns, arguing that constitutional interpretation should be guided by moral reasons and that it ought to be detached from any need to consult the framers' purposes or intentions.