I started off as a convinced Thomist from my first philosophical training with the French Jesuits at Jersey, under the guidance of the brilliant young Thomistic metaphysician, Andre Marc, from whom I developed a keen appreciation of the basic metaphysical structure of the real according to the vision of St. Thomas. Also decisive was my private reading of Joseph Marechal's whole history of Western thought, Point de depart de la metaphysique, culminating in his seminal Vol. V on Aquinas himself, in which he stressed the innate dynamism of the human intellect toward the Infinite Fullness of being as the ultimate foundation of all human inquiry; added to this was my underground reading of the then temporarily banned Blondel's Action (1st ed. 1893 - better than all the later more cautious revisions), which powerfully highlighted the complementary dynamism of the human will toward the same fullness of being as good. I have always held onto these two fundamental insights of St. Thomas as the basic for all human inquiry and search for the good, but I am not a full card-carrying member of the Transcendental Thomism school, for various technical reasons regarding whether and how they reached fully existential being as the basis of metaphysics by their method.
The historically important rediscovery of the profoundly existential character of St. Thomas's metaphysics, centered on the act of existence (esse) as the fountainhead of all perfection, both in creatures and in God, diversified by various modes of limiting essence, was just getting under way when I was at Jersey (1936-39), under the dramatic leadership of Etienne Gilson in the 5th edition of Le Thomisme, but I took full explicit possession of this deeply integrating insight into Aquinas's thought during my M.A. in philosophy at Fordham, under the direction of Anton Pegis, disciple and colleague of Gilson at Toronto. So I became what soon became known as an 'existential Thomist.'
The next significant phase of my philosophical development came during my Ph.D. studies at Louvain, under the well-known Thomists Van Steenberghen and De Raeymaeker. Here I shared in the exciting rediscovery of the central role of Neoplatonic participation in the metaphysics of Thomas, especially as the basic structure behind the relation of creatures to God, going far beyond what he could get from Aristotle alone - all this from my reading and discussions with Geiger, Fabro, De Finance, etc. Now I came to understand St. Thomas's entire metaphysical system as an original synthesis of Aristotelianism and Neoplatonism. I wrote my thesis precisely on the development of this synthesis in Thomas (summarized in the first, widely circulated article in my list of publications) a theme not yet widely known, it seems, in American Catholic Thomistic circles.
The last key element in my philosophical formation I picked up also during my doctorate at Louvain. All around me were blossoming the new movements of phenomenology, both the older more austere school of strict Husserlian phenomenology, which interested me less than the newer more existential interpersonalist phenomenologies of thinkers like Emmanuel Mounier, Martin Buber, Gabriel Marcel, Maurice Nedoncelle, John Macmurray, etc., and to a lesser extent Jean-Paul Sartre and Martin Heidegger. I plunged deeply into them for months, before returning to St. Thomas for my dissertation. I saw the need now for both these approaches as complementary to give us a more fully rounded understanding of the real. The interpersonal phenomenologies need the ontological grounding of dynamic substance or nature as a unified center for its many relations and its self-identity through time; Thomistic metaphysics needs to enrich the data it is seeking to explain by the more detailed concrete descriptions of the actual life of real persons provided so richly by phenomenology. A creative synthesis was needed. This I have tried to outline in Person and Being (l993), now in its fifth printing, and my widely circulated article, "To Be Is to Be Substance-in-Relation" (1992), which surprised many non-Thomists.
In doing this I identify myself with the growing, late 20th century movement called 'Personalist Thomism.' One leading center of this has been the Lublin School of Thomism (Poland), of which the best-known representative is Karol Wojtyla (Pope John Paul II), with his seminal book, The Acting Person and other similar writings.
Regarding Dietrich von Hildebrand: I knew von Hildebrand from teaching with him at Fordham for several years as well as from attending the soirées he was accustomed to hosting at his home. Although I do not closely agree with his philosophical method, I have always been impressed with the fullness of his Christian wisdom, his profound philosophical intelligence, and his rich culture.