Ancient author(s): Numenius, On the Good and other works as cited by Origen and Eusebius (link Greek text and full translation).
Comments: Numenius of Apameia in Syria (mid-second century CE), who was also associated with Rome, was an influential philosopher who focussed most of his attention on Plato. Yet Numenius also integrated other traditions within his perspective, including Pythagorean ones and, as these excerpts by other authors suggest, traditions of other wise “barbarian” peoples (so long as they did not conflict with Numenius’ understanding of Plato and were interpreted allegorically). According to Eusebius, Numenius’ view was that Plato was just about the equivalent of Moses speaking Greek. Legends about the life of Plato that circulated somewhat widely proposed his education among “barbarian” peoples, of course (on which go to this link [coming soon]).
Source of the translation: K.S. Guthrie, Numenius of Apamea: The Father of Neoplatonism (London: George Bell and Sons, 1917), public domain, adapted by Harland.
[Fragment 1a from book 1 of On the Good as cited by Eusebius, Preparation for the Gospel 9.7.1]
[beginning of the dialogue between a philosopher and a stranger not extant] . . . Philosopher: Regarding this matter, he will have to teach and interpret in the Platonic tradition, and fuse it with the teachings of Pythagoras. Then, as much as the teachings agree with Plato, he will have to cite the peoples (ethnē) who are held in honour, citing the initiatory rites, teachings and conceptions of the Brahmans, Judeans, Magians, and Egyptians. . . [following material not preserved].
[Fragment 1b from book 1 of On the Good as described by Origen of Alexandria, Against Celsus 1.15)]
How much better is the Pythagorean Numenius compared to Celsus [who actively critiqued Judeans and, as an offshoot, Christians]. By many proofs, Numenius has demonstrated that he is highly regarded because he investigated still other opinions, and he gathered what he considered true from many sources. In the first book of his treatise On the Good he also mentioned the Judeans among the peoples that believed God was incorporeal, and he did not hesitate from quoting the words of the prophets in his book, explaining them allegorically.
[Fragments 1c and 10a as described by Origen, Against Celsus 4.51]
But I know that Numenius – a man who has supremely well interpreted Plato, and who placed confidence in Pythagorean teachings – in many passages of his writings cites Moses and the Prophets, and has interpreted them allegorically in a not improbable way (as in his book On the Initiate, and in those On Numbers, and On Space). In the third book of On the Good, Numenius relates a story about Jesus without mentioning his name, however, and he interprets it allegorically. Whether he interpreted it rightly or wrongly must be discussed in another place. He also relates the story about Moses and Jamnes and Jambres [Exodus 7:10-12].
[Fragment 8 from book 2 of On the Good as cited by Eusebius, Preparation for the Gospel 11. 10.12-14]
Numenius the Pythagorean philosopher states directly: “For what is Plato but Moses speaking Attic Greek?”