(Tacuarembó, Uruguay, 1905 – 1982) Teacher, writer, pedagogue, and journalist. He was a teacher devoted to the rural environment, who fervently believed in a form of renewal of education in which students are not depersonalized. With a critical attitude, Sosa was interested in the psychology of children and how this intervened in their learning. He also delved into the subject of creative expression or ‘current interest,’ as he called it. His most revealing experience was the time he taught at the Rural School No. 56 in Canteras del Riachuelo, where he came face-to-face with the reality of rural schools in Uruguay, which were characterized by precariousness. Sosa designed a plan of action that began by improving the nutrition of his students and discussing with them the rules of discipline. He taught them subjects related to personal finance, such as how to calculate the price of merchandise, profits, and the value of wages. All his experience was captured in what became his masterpiece, the book Vida de un maestro [Life of a Teacher] (1935), considered a paradigmatic text of pedagogy. Two years later, he was dismissed and traveled to Argentina, where he was able to continue working in favor of students with the Santa Fe Teachers' Association.