On 19 August 1934, he was ordained as a priest and in 1936 he started studying philosophy at the Catholic University of Leuven, where he obtained a PhD degree in 1941 with a dissertation on the phenomenology of Edmund Husserl.
For the preparation of his PhD thesis he traveled to Freiburg, Germany in 1938, where he found, in the legacy of Edmund Husserl (1859–1938), more than 40,000 Gabelsberger stenography manuscripts and his complete research library.
In order to smuggle the documents out of Nazi Germany, he needed the support not only of the rector of the Catholic University of Leuven, but also of the Belgian government.
Van Breda also was able to convince Husserl's former assistants, Eugen Fink and Ludwig Landgrebe, to collaborate on the editing of these documents in Leuven.
In 1943 the documents were, for safety, distributed over different locations in Leuven, including a shelter in the cellar of the Institute of Philosophy and the Abbey of Postel.