Thomism and the Magisterium: From Aeterni Patris to Veritatis splendor

FROM THE TIME OF ALEXANDER IV (r. 1257-1261) the popes have been continuing champions of the method and doctrine of Thomas Aquinas (c. 1225-1274), the Doctor Communis (or Common Doctor), and have found them to be of great assistance in combating intellectual movements inimical to the Church. Two of the most energetic and aggressive of these movements in more recent times have been rationalism and modernism, movements priding themselves on their emancipation from authority and on their unrestricted exercise of freedom of thought. This exercise, they maintained, proved the fallacy of the Catholic conviction of the harmony between supernatural faith and natural reason. Rather, there was a disharmony, apparent if not real, between them—resoluble only, according to the rationalists, by reason eliminating faith, and, according to the modernists, by faith adapting to reason.

The Catholic response to these movements, especially to rationalism, was initiated by an ecumenical council, Vatican I (1869-1870), which sought, in the words of Cardinal Newman (1801-1890), "to restrain the freedom of thought, which of course in itself is one of the greatest of our natural gifts, and to rescue it from its own suicidal excesses," through affirming the existence of an "infallibility in religious teaching . . . adapted as a working instrument, in the course of human affairs, for smiting hard and throwing back the immense energy of the aggressive intellect." ² Rationalism was one avatar of that aggressive intellect, operating through an inexorable polemic evidently aimed at destroying the supernatural foundations of Catholicism.

A destructive force of this kind could be countered only by another avatar of the intellect, equally if not more aggressive, and arrayed in the panoply of logical argument. This avatar was Scholasticism, whose method, in the words of one of its most skillful users, Francisco Suárez (1548-1617), the Doctor Eximius (Extraordinary or Uncommon Doctor), is "the most apt for drawing truth out of darkness, and for assailing errors the most efficacious" (ad veritatem e tenebris eruendam aptissima est et ad impugnandos errores efficacissima). ³ But Scholasticism, though endowed with a common method, possessed at least nine variants in doctrine, some of them more evolved than others. The most evolved were four systems, whose principles consistently organized and integrated the multiple components of the entire field of Catholic doctrine, without in any way violating the norms of Catholic orthodoxy. Each system was named after its founder: the Bonaventurianism of Bonaventure (1221-1274), the Thomism of Thomas Aquinas, the Scotism of John Duns Scotus (1265-c. 1308) and the Suárezianism of Francisco Suárez.

Leo XIII (r. 1878-1903)

Of these four systems, the one chosen by the Magisterium to do battle with the rationalists was Thomism, a complex of theories comprehensive in scope, of great synthetic power and rigor of reasoning. However, like any philosophy, Thomism advanced principles that were controverted by other systems, Catholic included, and so could not serve as a basis for unifying proponents of tenets opposed to its own. For Thomism had postulates that were strongly critiqued by other Scholastic systems. The most important of these postulates was the real distinction of essence and existence. The Renaissance philosopher Cajetan (1465-1534) believed it to be the maximum fundamentum doctrinae Sancti Thomae, ⁴ "the greatest foundation of the doctrine of St. Thomas," but the Baroque philosopher Suárez thought differently. Ridiculum est, declared the Uncommon Doctor about the distinction, et plane inintelligibile, ⁵ "it is ridiculous, and entirely unintelligible." Earlier, Scotus too had been equally categorical. Simpliciter falsum est, the Subtle Doctor had remarked, quod esse sit aliud ab essentia, ⁶ "it is absolutely false, that existence be different from essence." The Thomists never succeeded in creating a consensus with the other Scholastics on this tenet, the meaning of which was a matter of serious contention even among themselves. ⁷ However, Thomism's architectonic symmetry...