"AETERNI PATRIS". - Opening words of the encyclical with which Leo XIII, on 4 August 1879, restored Thomistic philosophy to honor.
Having noted how false doctrines open the way to individual and social misconduct, it points out that sound philosophy disposes one to faith, shows the reasonableness of adherence to revelation, makes its content better understood, and defends its acquisition, while from faith it receives light and defense. The Fathers of the Church treasured whatever was sound in the philosophy of the gentiles and enlarged it with Christian wisdom. The Scholastics demonstrated better the harmony between reason and faith with refinement of logical procedures and sobriety of expression. St. Thomas stands out among all for his exceptional gifts of an angelic mind, reducing the scholastic currents to unity by eliminating and integrating.
The Church, which has always recognized this primacy of the Angelic Doctor, points out the harm done to science and society by the neglect of the moderns toward that philosophy. The Pontiff intends to restore it to honor for the solid formation of the clergy, for an effective apostolate among those learned men who claim to follow only reason, for the security of the social order, for the progress of all the sciences and arts that take light and direction from philosophy. It is not intended to accept from the Scholastics whatever has fallen, and whatever is gold must be enriched by all subsequent conquests.
So that the great reform should not remain on paper, Leo XIII, in the same year 1879, addressed an apostolic letter to Cardinal De Luca for the founding in Rome of a Thomistic academy dedicated to the study and defense of the restored philosophy. On 4 August 1880 he declared St. Thomas patron of all Catholic schools, and by a motu proprio of the same year he ordered a critical edition of all the works of St. Thomas, allocating to it a fund of 300,000 lire. A letter to Cardinal Goossens, Archbishop of Malines, dates from 1889, in which the Pope congratulates him on the founding of a higher institute of Thomistic philosophy at the University of Louvain, praises and confirms the choice of D. Mercier as its head, and promises to contribute to the expenses. Thus the great Pontiff extended to the universal Church what he had already done for his own diocese as bishop of Perugia where, in order to form a learned clergy, he had founded a Thomistic academy dating back to 1872, therefore even before that of Naples, which is from '74; among its members figured the names of Luigi and Anastasio Rotelli, Gabriele Boccali, Geremia Brunelli, Giuseppe Cernicchi, Giuseppe Pecci (brother of Gioacchino), Federico Foscati, Fabio Ferrini and Monsignor F. Satolli.
Whoever knows what the conditions of philosophy were, even in Catholic schools, before the A. P., understands the saying of Pius XI in the letter to Cardinal Bisleti of 1 August 1922 (AAS, [vol. 14] pp. 449-58): "If Leo XIII had no other merits toward the Church than this of having restored Thomistic philosophy, it would suffice alone to immortalize his memory." Cardinal Mercier was able in this way to summarize the effects of that reform: "The encyclical A. P. has effectively restored to honor the philosophy of the great masters of Scholasticism, has given back unity of teaching to the Catholic Church, has drawn the attention of learned men, strangers to the faith, to a quantity of ideas unknown to them" (op. cit. in the bibl., p. 328).