The rise of public schools or academies in the twelfth century, and the increase of intellectual activity, no doubt contributed greatly to the weakening of the papacy and the feudal aristocracy. This led the way to the rise and the establishment of the third estate in the realm—the middle classes—and to commercial enterprise. The enlightenment and the liberties of Europe from this period steadily advanced. Schools were erected almost everywhere; the thirst for knowledge increased. "The kings and princes of Europe seeing what advantages a nation may derive from the cultivation of literature and the useful arts, invited learned men to their territories, encouraged a taste for information, and rewarded them with honors and emoluments." But with such an increase of mental activity, many wild and dangerous doctrines and opinions were taught. Scholastic theology, Aristotelian philosophy, sacred and civil law, had their place and reputation by turns. It was about this time -the middle of the twelfth century—that the great universities of Oxford, Cambridge, and Paris were founded; with many others on the continent. Greek and Hebrew were studied, and lectures given in the way of expositions and commentaries on the holy scriptures, which the Lord could use in blessing to the students, and through them to others.
"To impose some restraint," says Dean Waddington, "on this great intellectual licentiousness—to revive some respect for ancient authorities—to erect some barrier, or at least some landmark, for the guidance of his contemporaries, Peter the Lombard published his celebrated "Book of the Sentences." Having studied for some time in the famous school at Bologna, he proceeded to Paris for the purpose of prosecuting his studies in divinity. The Book of the Sentences is a collection of passages from the Fathers, especially from St. Hilary, St. Ambrose, St. Jerome, and St. Augustine—a sad mixture, no doubt, of truth and error; but the Lord is above all and could use His own word, though intermixed with fashionable subtleties, for the conversion and blessing of souls. It long retained an undisputed supremacy in the theological schools, and its author was raised to great honors.