Ergo necesse est devenire ad aliquod primum movems, quod a nullo movetur; et hoc omnes intelligunt Deum.
- St. Thomas Aquinas (Summa Theologica, Pt. 1, qu. 2, art. 3)
(Therefore, it is necessary to arrive at a prime mover, put in motion by no other; and this everyone understands to be God.)
Si enim omnia mala impedirentur, multa bona deessent universo: non enim esset vita lionis, si non esset occisio animalium; nec esset patientia martyrum, si non esset persecutio tyrannorum.
- Id., qu. 22, art. 2
(If all evil were prevented, much good would be absent from the universe. A lion would cease to live if there were no slaying of animals, and there would be no patience of martyrs if there were no tyrannical persecution.)
Attributed to Aquinas, but unsourced:
Abuse does not rule out use.
Beware the man of one book.
Music is the exaltation of the mind derived from things eternal, bursting forth in sound.
The teachings of Thomas on the true meaning of liberty, which at this time is running into license, on the Divine origin of all authority, on laws and their force, on the paternal and just rule of princes, on obedience to the highest powers, on mutual charity one towards another - on all these and kindred subjects - have very great and invincible force to overturn those principles of the new order which are well known to be dangerous to the peaceful order of things and to public safety.
- Pope Leo XIII (reigned 1878-1903) (encyclical Aeterni Patris, 1879)
Today is the Roman Catholic feast day of St. Thomas Aquinas (ca. 1225-1274), the "Angelic Doctor" who became the greatest of the Church's medieval theologians and by the edict of Pope Leo XIII, Catholicism's "official" philosopher. Born in the family castle near Aquino, Italy - hence his name, originally Thomas of Aquino - Aquinas studied at Monte Cassino and Naples, entered the Dominican order, and became a pupil of the philosopher/saint Albertus Magnus. In his major work, the Summa Theologica (1267-1273), one of the bedrock texts of medieval scholasticism, he sought to reconcile Christian theology with the rationalism and natural philosophy of Aristotle and thus to show that faith and reason constitute two harmonious realms. In the world of Aquinas, everything is arranged in ascending order to God, the only necessary and self-sufficient being. Following a mystical experience in December 1273,
"Everything I have written seems like straw by comparison with what I have seen and what has been revealed to me..."
and thereafter, he ceased teaching and writing. Fittingly, Thomas Aquinas is the patron saint of academics, booksellers, students, and theologians.)
A typical "holy card" illustration of St. Thomas Aquinas: