31 If one considers all this well, he will easily see why the Church demands that future priests be instructed in philosophy "according to the method, doctrine, and principles of the Angelic Doctor," since, as we well know from the experience of centuries, the method of Aquinas is singularly preeminent both of teaching students and for bringing truth to light; his doctrine is in harmony with Divine Revelation, and is most effective both for safeguarding the foundation of the faith and for reaping, safely and usefully, the fruits of sound progress.
Source: Humani Generis (Vatican.va)