 In 1928 Fabro completed his pre-seminary studies and began studies of philosophy at the "Scuola Apostolica".After completing private studies at the Marian sanctuary at Ortonovo La Spezia in 1929 he transferred to the Curia Generalizia and International College of the Stigmatine Order at the convent of Sant'Agata dei Goti on "via Mazzarino" in Rome in order to begin his philosophy studies at the "Collegio Sant’Apolinare", the future Lateran University.In 1931, he completed his doctorate receiving the highest marks with a thesis entitled "L’oggettività del principio di causa e la critica di D. Hume" (The Objectivity of the Principle of Causality and Criticism of D. Hume).