Resumen: This article intends to identify, through a descriptive, analytical, and critical study, two moments in the national legal system. The first one refers to the role that the law played in the development and institutionalization of the Republic of Chile, whose legal culture was created under the principle of legality. The increasing recognition of this principle derived from its democratic value, which involved the superseding of other sources in the legal system. The second moment is related to the existence of a new paradigm: the constitutional and democratic state of law. It has progressively consolidated since the second half of the 20th century and its premise is the regulatory force and direct effectiveness of the Constitution under governmental agencies, particularly the courts of the Republic. The hypothesis of this research is that, even though there has been an evolution in the source system, the principle of legality is rooted in the Chilean legal culture. So, the prevalence of constitutional provisions over the law should highlight the need to intensify, in case of a conflict that requires the intervention of a court, the respect for the duality of parties in a legal proceeding as a guarantee for reducing judicial discretion.