The positivist methodological paradigm is overcome. It used to get to the norm taking as a presupposition solely the Law validly observed, according to the logics of head to bottom. Since we have many, and each time more complex, discussions demanded by national societies, and by the Law science itself, and also with attention to the impact of facts and regional powers, supra and international, arises related to the juridical thought the movement called postpositivism, which incorporates other elements to the Law science, such as, e.g., values, principles, politics, directions, procedures and arguments. Conceived like that, the Constitutional Law and the Law of the Constitution (both in form and content), impose a material interpretation - that is, an interpretation concerned with values accomplishment -; a reading which is also done from head tobottom, a reading which sees the Constitutional Law not only from the ad intra perspective, but also from the ab extra one. This is justified by the fact that the Constitution is conceived as an order of values. In this audience, a distinguished seat is held by the Constitutional Courts, which are supposed, at last, to decide about the constitutionality of laws and other acts related to public powers, and if such acts assimilate individual longings and values and are shared intersubjectively. Concerning Fundamental Rights, it is important to realize that the human dignity principle, with all its deonthic values in the articles 1st, III of the Brazilian Federative Constitution of 1988, and 1st of the Constitution of the Portuguese Republic of 1976, together with the article 1st of the Human Rights Universal Declaration, became the epicentre of the large catalogue of rights with fundamentality status, in its duality: rights, liberties and warranties, and social, economical and cultural rights; and, also, other open or indeterminate contents constitutional concepts, which irradiate their effects to every sub-constitutional juridical order. Even in collision situations or interest conflicts and pretensions in which the application of the topic catalogue of the constitutional interpretation principles, mainly the proportionality, the principle of principles, is an ethic imperative and of consciousness to impose to the one who suffers limitation and restriction concerning freedom and exercise of rights with the lesser possible human sacrifice.