This FERRAJOLI'S last contribution to debate on (neo) constitutionalism deserves five criticism: first, deductivist approach coherently adopted by the author from Teoria assiomatizzata del diritto to Principia iuris leaves too little a stance for interpretation and argumentation in legal reasoning; second, the very problem of law-morals relations is not discussed but eluded by him, fourth and fifth, the same deductivist approach must constrain FERRAJOLI to reduce principles to rules, to ignore the democratic role that could be carried out by a legislative and no-judicial balancing, and to provide a dubious monist answer to the pluralist question of conflict among rights.