14. Later on, the doctors of the middle ages, who are called Scholastics, addressed themselves to a great work-that of diligently collecting, and sifting, and storing up, as it were, in one place, for the use and convenience of posterity the rich and fertile harvests of Christian learning scattered abroad in the voluminous works of the holy Fathers. And with regard, venerable brethren, to the origin, drift, and excellence of this scholastic learning, it may be well here to speak more fully in the words of one of the wisest of Our predecessors, Sixtus V: "By the divine favor of Him who alone gives the spirit of science wisdom, and understanding, and who thou ages, as there may be need, enriches His Church  with new blessings and strengthens it with safeguards, there was founded by Our fathers, men of eminent wisdom, the scholastic theology, which two glorious doctors in particular angelic St. Thomas and the seraphic St. Bonaventure, illustrious teachers of this faculty, . . .with surpassing genius, by unwearied diligence, and at the cost of long labors and vigils, set in order and beautified, and when skilfuly arranged and clearly explained in a variety of ways, handed down to posterity.