Today we commemorate Leo and Irenaeus. According to Butler:
He (Leo) was by birth a Silician, eminent for his piety, and perfectly skilled in the Latin and Greek tongues, in the church music, and both in sacred and polite literature. Pope Agatho dying on the 1st of December, 681, he was chosen to fill the pontifical chair. He confirmed, by the authority of St. Peter, as he says, (writing to the zealous emperor Constantine Pogonatus, the sixth general council held at Constantinople, in which his predecessor St. Agatho had presided by his legates. In the censure of this council we find the name of Honorius, joined with the Monothelite heretics, Theodorus bishop of Pharan, and Cyrus, Sergius, Pyrrhus, Paul, and Peter of Constantinople. Pope Leo II. in his first letter to the bishops of Spain, gives the reason, because Honorius “did not extinguish the flame of the heretical doctrine in its rise, as it became the apostolical authority, but fomented it by negligence.” And in his letter to king Ervigius he makes the same distinction between Honorius and the others. It is evident from the very letters of Honorius himself, which are still extant, from the irrefragable testimony of his secretary who wrote those letters, and from others that he never gave into the Monothelite error; though had he fallen into heresy, this would have only hurt himself; nor is the question of any other importance than as an historical fact. Favourers are sometimes ranked with principals. Honorius had by unwariness, and an indiscreet silence, temporized with a powerful heresy, before his eyes were opened to see the flame which he ought to have laboured strenuously to extinguish when the first sparks appeared. St. Leo reformed the Gregorian chant, composed several sacred hymns for the divine office, and did many things for the advancement of religion, though he was only pope one year and seven months. He pointed out the path to Christian perfection no less by the example of his life, than by his assiduous instructions, and zealous exhortations; and was in a particular manner the father of the poor, whom he diligently relieved, comforted, and instructed with a most edifying tenderness, charity, and patience. He passed to a better life on the 23rd of May, 683, and was buried in the Vatican church on the 28th of June...
According to Butler:
THIS Saint (Irenaeus) was born about the year 120. He was a Grecian, probably a native of Lesser Asia. His parents, who were Christians, placed him under the care of the great St. Polycarp, Bishop of Smyrna. It was in so holy a school that he learned that sacred science which rendered him afterward a great ornament of the Church and the terror of her enemies. St. Polycarp cultivated his rising genius, and formed his mind to piety by precepts and example; and the zealous scholar was careful to reap all the advantages which were offered him by the happiness of such a master. Such was his veneration for his tutor's sanctity that he observed every action and whatever be saw in that holy man, the better to copy his example and learn his spirit. He listened to his instructions with an insatiable ardor, and so deeply did he engrave them on his heart that the impressions remained most lively even to his old age. In order to confute the heresies of his age, this father made himself acquainted with the most absurd conceits of their philosophers, by which means he was qualified to trace up every error to its sources and set it in its full light. St. Polycarp sent St. Irenæus into Gaul, in company with some priest; he was himself ordained priest of the Church of Lyons by St. Pothinus. St. Pothinus having glorified God by his happy death, in the year 177, our Saint was chosen the second Bishop of Lyons. By his preaching, he in a short time converted almost that whole country to the Faith. He wrote several works against heresy, and at last, with many others, suffered martyrdom about the year 202, under the Emperor Severus, at Lyons.