At the request of Aquinas—so it is assumed; the source document is not clear—he undertook a complete translation of the works of
Aristotle directly from the Greek or, for some portions, in a revision of existing translations. The reason for the request was that many of the copies of Aristotle in Latin then in circulation had originated in
Spain (see
Toledo School of Translators), from Arabic whose texts in turn had often passed through
Syriac versions rather than being translated from the originals. Aquinas wrote his commentary on Aristotle's
De Anima, the translation of which from the Greek was completed by Moerbeke in 1267, while Aquinas was regent at the
studium provinciale at the convent of
Santa Sabina in Rome, the forerunner of the 16th-century College of Saint Thomas at
Santa Maria sopra Minerva and the
Pontifical University of Saint Thomas Aquinas, Angelicum. William of Moerbeke was the first translator of the
Politics (c. 1260) into Latin, as the
Politics, unlike other parts of the Aristotelian corpus, had not been translated into Arabic. He was also responsible for one of only three medieval Latin translations of Aristotle's
Rhetoric. William's translations were already standard classics by the 14th century, when
Henricus Hervodius put his finger on their enduring value: they were literal (
de verbo in verbo), faithful to the spirit of Aristotle, and without elegance. For several of William's translations, the Byzantine Greek manuscripts have since disappeared; without him the works would be lost. William also translated
John Philoponus and mathematical treatises by
Hero of Alexandria and
Archimedes. Especially important was his translation of the
Elements of Theology of
Proclus (made in 1268), because the
Elements of Theology is one of the fundamental sources of the revived
Neo-Platonic philosophical currents of the 13th century. His translation of Proclus' commentary on Plato's
Parmenides, which included Plato's dialogue up to 142b in
Stephanus pagination, made this text available in Latin for the first time. Some important shorter texts of Proclus, such as "On Providence", "On Providence and Fate", and "On the Existence of Evil", are preserved only in William of Moerbeke's translations. The
Vatican collection holds William's own copy of the translation he made of the greatest
Hellenistic mathematician,
Archimedes, with commentaries of
Eutocius, which was made in 1269 at the papal court in Viterbo. William consulted two of the best Byzantine Greek manuscripts of Archimedes, both of which have since disappeared. The manuscript, in his own hand, was in the exhibition
Rome Reborn: The Vatican Library & Renaissance Culture at the
Library of Congress in 1993. == In popular culture ==