Temporal validity of norms is tied to due process and legal certainty principles. Likewise, a norms possibility to be applied at different moments in time is based in certainty and fairness principles. It is with this background and framework that the subject of retroactivity is addressed, understanding its nature, aims and reach, arguing that this form of application of norms does not undermine the unity and coherence of a legal system.Abstract:Temporal validity of norms is tied to due process and legal certainty principles. Likewise, a norms possibility to be applied at different moments in time is based in certainty and fairness principles. It is with this background and framework that the subject of retroactivity is addressed, understanding its nature, aims and reach, arguing that this form of application of norms does not undermine the unity and coherence of a legal system.La validez temporal de las normas se vincula a los principios de legalidad y seguridad jurídicas. La capacidad de una norma de operar de manera diferenciada en el tiempo se fundamenta, asimismo, en razones de certeza jurídica y de justicia. El tema de la retroactividad es analizado con el objeto de comprender su naturaleza, fines, límites y alcances como institución jurídica, no solamente para entender su función en el sistema jurídico, sino también para hacer evidente que esta forma de aplicación de las normas no atenta contra las ideas de unidad y coherencia del sistema jurídico.Abstract:Temporal validity of norms is tied to due process and legal certainty principles. Likewise, a norms possibility to be applied at different moments in time is based in certainty and fairness principles. It is with this background and framework that the subject of retroactivity is addressed, understanding its nature, aims and reach, arguing that this form of application of norms does not undermine the unity and coherence of a legal system.

Instituto de Investigaciones Jurídicas de la UNAM