The Dominican professors of theology at this time were Hugh of Metz and Elias Brunetus. It was as teacher in the school of Elias that the saint began to expound Holy Writ, and the writings of Peter Lombard. His influence over young men far surpassed that of any other master. They were conscious that his teaching had something about it of another world; and the feeling crept over all, and finally mastered them, that he spoke as one "having authority." The opinions he then formed, he committed to writing, and held them and defended them with little change in his maturer years. From his youth he had dedicated himself to Wisdom as his spouse. Only one thing he asked for—that was wisdom. Rainald said, "One thing I know of him, that it was not human talent, but prayer, which was the secret of his great success. This was his daily prayer: 'Grant me, I beseech Thee, O merciful God, prudently to study, rightly to understand, and perfectly to fulfil that which is pleasing to Thee, to the praise and glory of Thy Name.'" When a child, if conversation did not turn on God, or on matters which tended to edification, the Angelical Doctor would go away; he used to wonder how men, especially religious men, could talk of anything but God or holy things. He wept for the sins of others, as if they had been his own.
Though ever dwelling in the unseen kingdom, he was keenly alive to the tendency of the intellectual world around him. His saintliness, and his great ability, seem to have pointed him out as destined to sway the philosophical and theological tendencies of an age in which the human mind was in a condition of flux. The corroding rationalism of the school of Abelard, and the dissolving mysticism of the East, had to be faced, and to be withstood. Thomas fixed himself, therefore, on the immoveable basis of authority, and grounded his teaching on the monastic methods of the "Sentences." Doubtless the surprise caused by his distinctions, and the admiration created by his novelty in argument, proceeded in great measure from his vivid apprehension of the work he had to do, of the enemy he was contending with, and of the powers by which alone that enemy could be overthrown. He followed Albert, but his teaching was more incisive, more definite, more strictly to the point.
Many of his disciples became distinguished men. S. Thomas assisted others beside his own pupils. Sovereigns, cardinals, bishops, superiors of orders, and professors, wrote to him for advice, and for solutions of their difficulties. The Opusculum on the difference between the Divine and human word; and the somewhat larger treatise, on the nature of the intellectual word, are full of close reasoning; and state principles which are fundamental regarding the method of human knowledge.
One of the most important of his treatises is that addressed "ad Fratrem Rainaldum," on the nature of the Angels. It was begun during his bachelorship, but he never got beyond the 30th chapter. It shows his grasp of some of the cardinal questions of the day, and how masterfully he dealt with errors of the most promising minds in the Paris schools.
But whilst thus engaged upon the Scriptures and the Lombard, S. Thomas was frequently in the pulpit, and he regularly delivered lectures to crowded halls. His versatility, his power of abstraction, his astonishing memory, his zealous husbanding of time, carried him with ease through works which would have broken the spirit of any ordinary man. He possessed that marvellous gift which Origen and Cæsar are said to have had, of being able to dictate to three or even four scribes on different and difficult subjects at the same time, and that, too, without losing the thread of each argument.
Frigerius says that, as Professor, he elucidated the Sentences with such sublimity of thought that he seemed rather the author of the work than its expositor. Tocco, "that he surpassed all the masters of the University, and by the lucidity of his expositions drew, beyond all others, the intelligences of his disciples towards a love of science." Students from every part of Europe flocked around his chair.
In touching on S. Thomas's commentary on the "Sentences," the influence of Alexander Hales must not be forgotten, but he far eclipsed the Minorite in his proofs of the non-eternity of the world—a question of momentous importance in the Middle Ages, as well as in his discussion of the possibility and fitness of the Incarnation. Thomas carried his teaching on Grace to such perfection that in the Middle Ages it was always received as a standard authority.
If judged by its bulk, this "Commentary" would seem sufficient to have occupied a life. It fills over 1250 pages of the large quarto Parma edition, printed in double columns. It is a monument of ceaseless labour, great skill, and patient thought.
The work of the Lombard is a confusion compared with the lucid style and admirable arrangement of the saint. In place of the crabbed inverted language of Peter, we have the simple, logical, direct use of words, which go straight to the point, and express the complete idea. He has these weighty words on the subject of theology, "Since the end of all philosophy is contained within the end of theology, and is subservient to it, theology ought to command all other sciences, and turn to its use those things which they treat of." He adds, "The more sublime knowledge is, so much greater is its unity, and so much wider the circle of its expansion, whence the Divine intellect, which is the most sublime of all, by the light, which is God Himself, possesses a distinct knowledge of all things." He also shows how the intellect becomes illuminated when led by faith, illustrating the motto of the monastic school, "Nisi credideritis, non intelligetis." And he shows that theology is deduction, and philosophy induction; and that the basis of theology must be authority, i.e., a Revelation.
During the Lent of 1250 or 1253, the city patrol came in collision with a party of students, killed one of them, wounded three others, and carried them off to prison. The secular professors of the University refused to lecture, until the beadles were punished, but the Dominican and Franciscan teachers went on with their lectures. When redress had been granted to the University for the outrage, that body drew up an oath to observe all the laws of the University, which it was intended should be taken by all persons before taking the degree as master. The regulars refused to take it; then the University issued a decree, declaring the friars excluded from its body, and deprived of their chairs. The latter appealed to Rome. The pope commissioned the bishop of Evreux, and Luke, canon of Paris, to re-establish the friars in their chairs, which was done. This pope dying, his successor issued a bull, binding all to stop teaching in case of insult, but re-establishing the friars. The king, returning home, stopped the execution of the papal briefs. The pope issued another bull more stringent than the first. Since 1256, S. Thomas had been lecturing as licentiate. At the same time he was enjoying the friendship of S. Bonaventura, who was lecturing under the Franciscan professor. Both men exhibited, in a striking manner, the fundamental quality of the order to which they respectively belonged. Bonaventura loved to look into the placid, earnest soul of Thomas, as into a deep sea, with its marvellous transparency, and awful stillness; whilst Thomas was roused and brightened by the ardent gushing nature of his friend. S. Thomas was angelical; S. Bonaventura was seraphic—the one, the deep thinker; the other, the tender poet. Thomas was famous in the schools for the keenness of his thought, and for his depth and clearness; Bonaventura for his eloquence and vivacity in exposition; the former was a child of contemplation, the latter of activity. Once S. Thomas asked S. Bonaventura to show him the books out of which he got his sublime thoughts. "There is the book," replied S. Bonaventura, pointing to the crucifix. During this time S. Thomas wrote his "Exposition on the Apostles' Creed, the Lord's Prayer, the Angelic Salutation, the Ten Commandments, and the Law of Love." Another work on the "Articles of the Faith and the Sacraments" falls within this period, as well as a commentary on Isaiah.