AETERNI PATRIS
ENCYCLICAL OF POPE LEO XIII
ON THE RESTORATION OF CHRISTIAN PHILOSOPHY
Pope Leo XIII
Given at St. Peter’s, in Rome, the fourth day of August, 1879, the second year of our pontificate.

To the Patriarchs, Primates, Archbishops, and
Bishops of the Catholic World in Grace and
Communion with the Apostolic See.

**The quotes below are all taken from Aeternis Patris. The titles have been added.

The Chief & Master Scholastic:
Among the Scholastic Doctors, the chief and master of all towers Thomas Aquinas, who, as Cajetan observes, because “he most venerated the ancient doctors of the Church, in a certain way seems to have inherited the intellect of all.”

Bulwark & Glory of the Catholic Faith:
The doctrines of those illustrious men, like the scattered members of a body, Thomas collected together and cemented, distributed in wonderful order, and so increased with important additions that he is rightly and deservedly esteemed the special bulwark and glory of the Catholic faith.

The Sun that Warms the World:
With his spirit at once humble and swift, his memory ready and tenacious, his life spotless throughout, a lover of truth for its own sake, richly endowed with human and divine science, like the sun he heated the world with the warmth of his virtues and filled it with the splendor of his teaching.

Defeated the Errors of Former Times:
And as he also used this philosophic method in the refutation of error, he won this title to distinction for himself: that, single-handed, he victoriously combated the errors of former times, and supplied invincible arms to put those to rout which might in after-times spring up.

Reason Borne on the wings of St. Thomas Aquinas:
Again, clearly distinguishing, as is fitting, reason from faith, while happily associating the one with the other, he both preserved the rights and had regard for the dignity of each; so much so, indeed, that reason, borne on the wings of Thomas to its human height, can scarcely rise higher, while faith could scarcely expect more or stronger aids from reason than those which she has already obtained through Thomas.

A King in the Academic Kingdom:
All know how the fame of these seats of learning [the great universities] grew with their years, and that their judgment, often asked in matters of grave moment, held great weight everywhere. And we know how in those great homes of human wisdom, as in his own kingdom, Thomas reigned supreme; and that the minds of all, of teachers as well as of taught, rested in wonderful harmony under the shield and authority of the Angelic Doctor.

Presided over Ecumenical Councils:
The ecumenical councils, also, where blossoms the flower of all earthly wisdom, have always been careful to hold Thomas Aquinas in singular honor. In the Councils of Lyons, Vienna, Florence, and the Vatican one might almost say that Thomas took part and presided over the deliberations and decrees of the Fathers, contending against the errors of the Greeks, of heretics and rationalists, with invincible force and with the happiest results.

The Special Glory of St. Thomas – the Summa upon the Altar:
But the chief and special glory of Thomas, one which he has shared with none of the Catholic Doctors, is that the Fathers of Trent made it part of the order of conclave to lay upon the altar, together with sacred Scripture and the decrees of the supreme Pontiffs, the Summa of Thomas Aquinas, whence to seek counsel, reason, and inspiration.

The Incomparable Man:
A last triumph was reserved for this incomparable man-namely, to compel the homage, praise, and admiration of even the very enemies of the Catholic name. For it has come to light that there were not lacking among the leaders of heretical sects some who openly declared that, if the teaching of Thomas Aquinas were only taken away, they could easily battle with all Catholic teachers, gain the victory, and abolish the Church. A vain hope, indeed, but no vain testimony.

Exhortations to Study St. Thomas Aquinas

We have learned with great joy that many members of your order, venerable brethren, have taken this plan to heart; and while We earnestly commend their efforts, We exhort them to hold fast to their purpose, and remind each and all of you that Our first and most cherished idea is that you should all furnish to studious youth a generous and copious supply of those purest streams of wisdom flowing inexhaustibly from the precious fountainhead of the Angelic Doctor.

While, therefore, We hold that every word of wisdom, every useful thing by whomsoever discovered or planned, ought to be received with a willing and grateful mind, We exhort you, venerable brethren, in all earnestness to restore the golden wisdom of St. Thomas, and to spread it far and wide for the defense and beauty of the Catholic faith, for the good of society, and for the advantage of all the sciences.