Professor Betzabé Marciani Burgos from the Pontifical Catholic University of Peru, has been a guest of the Department of Law for two months (01/02/2019-31/03/2019). During her stay she conducted a series of lectures starting from the general theme: “Los conflictos de derechos en el Estado Constitucional y la dimensión argumentativa del Derecho”. In particular: In recent years in many Latin American countries the implementation of rights has found a new strength, This situation generates, at the same time, enthusiasm and concern for the growing judicial activism. It therefore seems necessary to develop an adequate theory of legal argumentation, also because of the growing number of cases considered difficult. Professor Marciani’s lessons are based on the analysis of some cases to deal with legal problems, thus stimulating reflection and debate among learners in order to develop their reflective and argumentative abilities. We can find the same themes and problems in Europe too, just like the defense of individual and group rights in an area of cultural diversity; freedom of expression in the information society.