He held that Plato and Aristotle were in substantial agreement, that God has made men free to adopt the mode of worship they prefer, and that Christianity and Hellenism were merely two forms of the one universal religion.
The Dictionary of Christian Biography and Literature to the End of the Sixth Century by Henry Wace notes Charito and their son had joined the Emperor by the end of 363, a fact that can be determined by a passage of Themistius.
Zabarella consulted newly recovered Greek commentators such as Alexander of Aphrodisias, Philoponus, Simplicius and Themistius, as well as medieval commentators like Thomas Aquinas, Walter Burley and Averroes.
Other important philosophers and thinkers in the Sicilian Questions referred to are, in alphabetical order, Alexander of Aphrodisias, Anaxagoras, Berosus, Crates, Diogenes, Euclid, Al-Farabi, Galen, Al-Ghazali, Al-Hallaj, Ibn Bajja (Avempace) Ibn Sina (Avicenna), Iamblichus, Mellow, Parmenides, Pythagoras, Plato, Socrates, Themistius, Theophrastus, and Zeno of Elea.