Christ came into the world at the inflection point St. Paul called “the fullness of time” (Gal. 4:4).
The Jews were looking for the Messiah; the Greeks had gotten as far as unaided human reason could get through philosophy; and the Romans had pacified a barbaric world through the might of an Empire spanning three continents.
It was at this crossroads of revealed religion, philosophy, and civilization that Christ came into the world, forever uniting and fulfilling the genius of the Jews, the Greeks, and the Romans by the Incarnation of the Divine Word, the Logos, by Whom the entire universe was created and ordered.
It was at this crossroads that Christendom—the civilization born from the heart of the Catholic Church—came into being.
The Great Tradition is all that is True, Good, and Beautiful that preceded, and proceeded from, the heart of Christendom.
It is the tradition that formed Saints, Sages, and Statesmen.
It is the law of Moses, the prophets, the Scriptures, and the New Covenant of Jesus Christ that fulfilled them all. It is the philosophy of Socrates, Plato, and Aristotle, and every Sage in whose mind reason maintains her compass. It is the laws and institutions of Rome, and the arts of civilization. All of these prepared the way, and were indeed forever united and fulfilled by the Incarnation of the Son of God.
This in turn created the civilization of Christendom, from whose bosom was born Saints like Athanasius, Augustine, Francis of Assisi, and Thomas Aquinas; Sages like Boethius, Albert the Great, Pascal, and Hildebrand; Statesmen like Justinian, King Louis IX, St. Thomas More, and Blessed Charles; and the poetry of Dante, the art of Michelangelo, and the music of Mozart.
This Great Tradition ennobled and redeemed the human race. It enlightened minds, inspired hearts, and liberated families, nations, and empires from thralldom to Satan.
And can do so again.