St Peter Damian, Bishop, Confessor, and Doctor
"As a light of souls, he was to be placed on the candlestick" (Gospel), and became bishop of Ostia and cardinal. He rendered immense services to the Sovereign Pontiffs by his learning, his commissions as legate and many other works. Taking his share in the apostolic life of Jesus, he combated the heresy of the Simonists and died at Faenza in 1072. Leo XII gave him the title of Doctor of the Church.
Let us imitate in his ardour for penance, St. Peter Damian, who contributed so much by his example and counsel, to spread the penitential practice of the discipline as an atonement for sin.
In medio Ecclesiae aperuit os ejus: et implevit eum Dominus spiritu sapientiae et intellectus: stolam gloriae induit eum. * Bonum est confiteri Domino: et psallere nomini tuo, Altissime.
In the midst of the Church the Lord opened his mouth: and He filled him with the spirit of wisdom and understanding: He clothed him with a robe of glory. * It is good to give praise to the Lord: and to sing to Thy name, O most High.
(Ecclesiasticus 15:5 and Psalm 91:2 from the Introit of Mass)
Concede nos, quaesumus, omnipotens Deus: beati Petri, Confessoris tui atque Pontificis monita et exempla sectari; ut per terrestrium rerum contemptum aeterna gaudia consequamur.
Grant us, we beseech Thee, O almighty God, to follow the admonitions and examples of blessed Peter, Thy confessor and bishop; that by despising earthly things we may obtain eternal joys.
From the Catholic Encyclopaedia: http://www.newadvent.org/cathen/11764a.htm