The aim of this article is to provide an approach to the study of the relations between psychology and Roman Catholic Scholasticism in the making of Spain as a modern nation-state. The crucial period in this process-extending from the beginning of King Alfonso XII's reign in 1875 to the proclamation of the Second Spanish Republic in 1931-is considered. Attention is focused on Ethics textbooks published by Spanish Scholastic authors throughout the period. Through these school manuals, young students were trained in the ideas of citizenship and social coexistence held by the Catholic Church. An analysis of these didactic, programmatic works shows the central role played by the theory of faculties and modern psychological technologies (psychopedagogy, psychopathology, psychotechnics) in the Scholastic outlook. Thus, an attempt is made to show that psychology was used by Spanish Scholasticism as a way of legitimating a reactionary view of Spain, which eventually led to the emergence of National-Catholicism as the official ideology of the Franco regime (1939-1975).