St. Thomas Aquinas' chastity of the eyes, Commentary on Job, Ch. 31, First Lesson

St. Jerome, Letter 52, To Nepotian, 5, 15

St. Possidius, Life of St. Augustine, Ch. 26

Abbe Hulot on chastity of the eyes, Balls And Dancing Parties Condemned By The Scriptures, Holy Fathers, Holy Councils, pg. 40-41

St. Felix of Cantalice's chastity of the eyes

"He walked with his eyes cast down, but his heart was always raised to God by prayer. No objects seemed to turn his mind from heavenly things, because he restrained his eyes from curiosity or vanity, and considered God and His will in every thing...
He always preserved his purity unspotted both in mind and body, guarding it by the strict watchfulness over his sense, especially his eyes: and he never looked any woman in the face."
The Lives of the Fathers, Martyrs, and Other Principal Saints, Vol IV-VI, pg. 376

Ven. Fulton Sheen on youth and zealotry

"From the beginning of the early Church the Jews persecuted Christians, as is obvious in the Acts of the Apostles, and they would do the same even now, if they were able."

St. Thomas Aquinas, Commentary on Galatians

"The old ancients, they used to sometimes read the entrails of birds to find out what the future was, Today we read the entrails of machines to discover what we ought to do."

Ven. Fulton Sheen, Life is Worth Living, Episode 94, Three Kinds of Proposals

If it is dangerous to be negligent in steering a ship in the midst of the sea, how much more perilous to abandon it in a storm with the waves running high; and even so the Church which makes its way through the ocean of this world like a great ship, buffeted in this life by diverse waves of temptation, is yet not to be abandoned.

St. Boniface of Mainz, Epistle to Archbishop Cuthbert of Canterbury VIII

"What can the world promise? Whatever it may promise, it promises to someone who will perhaps die tomorrow."

St. Augustine, In 1 John, Homily 3

"Being a Catholic will never prevent you from sinning. But I can tell you one thing: it will take all the fun out of it."

Ven. Fulton J. Sheen, A Catholic Catechism, Lesson 50: World, Soul, and Things

"The world is a spectacle that will soon be over."

St. Alphonsus Liguori