This article aims to reconstruct the pedagogy of Leonor Serrano, a Spanish school inspector working and developing her theories between 1914 and 1939. We use an interrogative-analytical methodology based on content analysis of her texts to reconstruct her educational theory. The theoretical deductive elements are uncovered in the analysis of the answers Leonor Serrano gives to the "basic questions of education", issues that provide the bases for the scientific field of the theory of education to define a specific pedagogy and are identified through a process of historical-educational review. The study outcome is an explanatory narrative. The paper ends with a discussion of the method and the results.