that knowledge exists for the service of the Church, and that the Church, while she instructs society, will claim complete obedience to her decrees. The _ipse dixit_ of the Dominican author of the "Summa" is law. Such frescoes, by no means uncommon in Dominican cloisters, still retain great interest for the student of scholastic thought. In the church of S. Maria Sopra Minerva at Rome, where Galileo was afterwards compelled to sign his famous retractation, Filippino Lippi painted another triumph of S. Thomas, conceived in the spirit of Taddeo Gaddi's, but expressed with the freedom of the middle Renaissance. Nor should we neglect to notice the remarkable picture by Traini in S. Caterina at Pisa. Here the doctor of Aquino is represented in an aureole surrounded by a golden sphere or disc, on the edge of which are placed the four evangelists, together with Moses and S. Paul.[137] At his side, within the burnished sphere, Plato and Aristotle stand upright, holding the "Timaeus" and the "Ethics" in their hands. Christ in glory is above the group, emitting from His mouth three rays upon the head of S. Thomas. Single rays descend in like manner upon the evangelists and Moses and S. Paul. They, like Plato and Aristotle, hold open books; and rays from these eight volumes converge upon the head of the angelical doctor, who becomes the focus, as it were, of all the beams sent forth from Christ and from the classic teachers, whether directly effused or transmitted through the writers of the Bible. S. Thomas lastly holds a book open in his hand, and carries others on his lap; while lines of light are shed from these upon two bands of the faithful, chiefly Dominican monks, arranged on each side of his footstool. Averroes lies prostrate beneath his feet with his book face downwards, lightning-smitten by a shaft from the leaves of the volume in the saint's hand, whereon is written: _veritatem meditabitur guttur meum et labia mea detestabuntur impium_.[138]