Evolutionary legal analysis of the relations between the Catholic Church and the State in Chile during the 20th century. Examines the separation in the Constitutions of 1925 and 1980 and subsequent social, legal, and political changes. Includes the Law on the Legal Constitution of Religious Organizations (1999), the new Civil Marriage Law (2004), and reflects on religious freedom and current challenges, with an emphasis on secularization and new social and regulatory paradigms.