What place belongs to history within constitutional studies? Can the historical reference be more than an addition or a simple demonstration erudite among analysts of constitutions? Are you responsible to history a guide function, guiding and explanatory at the same time, of constitutional developments? These are some of the questions that this essay attempts to answer. Gustavo Zagrebelsky in it makes a light path by tensions between history and constitutional texts in the eighteenth and nineteenth centuries. The picture thus drawn, which the constitutionalists of the XXI century are heirs, gives rise to both pessimism and optimism. The first due to the persistence of a positivist view of law, for which the analysis of the legal systems is limited to the explanation of the rules that compose them. The latter as a result of the revaluation is experiencing the story for constitutional science in the context of constitutionalism beyond national borders. For only appealing to history can be understood, for example, the formation of a European constitutional sphere.