 This dissertation repeats the traditional criticism of Hume taught in the early 20th century.Fabro began studying for a Licentiate in theology at the Pontifical International Institute "Angelicum", the forerunner of the Pontifical University of St. Thomas Aquinas, "Angelicum" On December 20, 1934, he received a prize from the Pontifical Academy of St. Thomas Aquinas for his monograph entitled "Il principio di causalità, origine psicologica, formulazione filosofica, valore necessario ed universale" ("The Principle of Causality, its Psychological Origin, Philosophical Formulazation, and Necessary and Universal Value").On September 8, 1934, Fabro was transferred to his Order's religious house at the Church of Santa Croce in Via Flaminia where he was assigned as church organist; he was to remain at Santa Croce until his death.