A democratic government should be restricted by law. That’s the main idea of constitutionalism. The procedures established to take social decisions in a constitutional democracy must respect some limitations, like fundamental rights. The logic of constitutionalism is the logic of the procedural.
The legitimacy (justice or fairness) of a procedure can be explained using the scheme proposed by Rawls. There are procedures whose results can be evaluated with reference only to the rules that define the procedure itself. Additionally, there are procedures that can be examined with regard to criteria external to them. In this paper I will the quasi-pure procedural approach that admits that is substantive (not procedural) criteria external to political procedures, like human rights principles, but these criteria and the demands that derives from these, can be justified and applied in very different ways or admit varying degrees of compliance.