Urban wished to reward his distinguished services. The great wealth he offered, the saint directed should be given to the poor. He declined the offer of the patriarchate of Jerusalem, and, shortly after, the honour of a cardinal's hat, for Thomas had thoroughly realized both the mysterious treasures of voluntary poverty and the hidden force of evangelical humility.
The pope, finding he could not attach our saint to his court by the ties of honours or riches, bade him lecture at the various places where he took up his abode, Viterbo, Orvieto, Perugia, Fondi. Everywhere a prodigious number of pupils pressed around his chair. The churches were too small to receive the numbers who flocked to hear him. Historians only record one course of Lent sermons preached by him in Rome.
One Christmas-eve he held a disputation with two Jewish Rabbis at the villa of a cardinal. After asking them to return in the morning, he passed the whole night in meditation and prayer. The Rabbis returned in the morning, but it was to ask for baptism.
In 1263, Thomas was sent to the Dominican general chapter, held in London, as "definitor," in the name of the Roman province.
Soon after his return to Italy, S. Thomas proposed to Urban the institution of a special festival throughout the Catholic Church in honour of the Holy Sacrament. When Urban was archdeacon of Liége, in the convent of Mont Cornillon, near one of the gates of the city, a poor religious named Juliana (April 3rd), as she prayed had a vision of the moon shining in all its splendour, but disfigured by one little breach. She desired to know its meaning, and an inner voice told her it was the Church, and that the breach represented the defect of a festival in honour of the Blessed Sacrament. After a time, an office in honour of the Blessed Sacrament was drawn up by a young religious. Robert de Torote, bishop of Liége, in 1246, appointed Thursday, in the octave of Trinity, for this feast.
Henry of Gueldres succeeded him as bishop, and treated the revelations of Juliana as folly. She died on 5th April, 1258, and left as a legacy to her friend Eve the duty of reviving this festival. Eve was a recluse built up in a niche of a wall near the church of S. Martin, at Liége, and through the hole by which she received light, air, and alms, besought the canons as they passed to seek out the bishop and entreat him to write to the pope on the subject of the proposed festival. The bishop did not disdain this humble prayer, but transmitted her message to the pope, who received at the same time the petition of the first doctor in the Church to the same effect. He wrote a letter to the poor recluse of S. Martin, in 1264, telling her of the issuing of a bull in answer to her prayer, and transmitting a copy of the office which the Angelical doctor had drawn up.
Clement IV. succeeded Urban on the 22nd of February, 1265. Shortly after his elevation he issued a bull appointing S. Thomas archbishop of Naples, and conferring on him the revenues of the convent of S. Peter ad Aram. But the pope was induced to recall it by the prayers and tears of our saint.
In this year we must place the first commencement of the "Summa Theologiæ." This was the greatest monument produced by that age.
Disgusted, as S. Thomas says in his preface, at the exuberance, the disorder, the obscurity of the scholastic treatises then extant, he had conceived the plan of a methodical and luminous summary, which should contain the whole of Christianity from the existence of God to the least precept of morality, all the speculative and practical points of revealed truth following in natural and logical order.
The saying current at the time, that "some proposition was true according to the master, Aristotle, but false according to the Gospel," clearly shows the antagonistic attitude occupied by the two powers in the opinion of the schools.