[1][2] His reputation as a teacher and a translator of Aristotle was very great, and he was selected as secretary by Pope Nicholas V, an ardent Aristotelian.

The bitterness of his attacks upon Plato (in the Comparatio Aristotelis et Platonis of 1458,[3] described by historian James Hankins as "one of the most remarkable mixtures of learning and lunacy ever penned"), which drew forth a powerful response from Bessarion (In calumniatorem Platonis, printed in 1469)[4] and the manifestly hurried and inaccurate character of his translations of Plato, Aristotle and other classical authors, combined to ruin his fame as a scholar, and to endanger his position as a teacher of philosophy.

The indignation against George on account of his first-named work was so great that he would probably have been compelled to leave Italy had not Alfonso V of Aragon given him protection at the court of Naples.

Additionally, an earlier work on Greek rhetorical principles garnered him wide recognition, even from his former critics who admitted his brilliance and scholarship.

[5] For a complete list of his numerous works, consisting of translations from Greek into Latin (Plato, Aristotle and the Fathers) and original essays in Greek (chiefly theological) and Latin (grammatical and rhetorical), see Fabricius, Bibliotheca Graeca (ed.