Justin's Hortatory Address is interesting. In it we see an apologetic for a convert from Greek philosophy and religion to early Roman Christianity. What is more interesting is the appeal to the so-called perennial philosophy as an apologetic defense against Greek polytheism. Many fathers cite the tradition that Pythagoras, Plato, Orpheus and Sibyl relate a tradition that comes from Egypt, not as paganism, but from Moses. Indeed, this is very plausible, though discarded by moderns. The reason it's discarded is that it presupposes the veracity of the biblical texts, particularly the Law and prophets, which were the first to be attacked by Luther's reformation sons and daughters through higher criticism, through Satanically-inspired men like Julius Wellhausen.
Justin refers interestingly to The Timaeus as well, which I recently read, where an Egyptian priest relates to Solon, who then relates to Socrates, the ancient tradition of creation that is somewhat monotheistic. So we see that the ancient occult lineage of polytheism at places intertwines with the true monotheistic lineage as maintained by the prophets of the true God, but most strikingly, what emerges is that the Egyptian and Greek lineage of this "tradition" clearly become corrupted and introduce polytheism. The Timaeus does just this, introducing demiurges and co-creator gods along with God. Many scholars retrace this Egyptian period to Rameses II and the Hyksos, which may have been the period when Joseph ruled in Egypt. This also raises interesting questions about Egyptian monotheism and the resurrection. It makes sense that, given the presence of the Jews in Egypt, the Egyptians would have adapted some of their doctrines, especially if Moses and Joseph had been among them and taught the doctrine of the one, true and pure religion.
Thus, the perennial philosophy as it is so-called is hard to decipher and hard to pin down, but the point I have been making above cancels out the blasphemies and attacks on God that are common in liberal circles, as well as modern new world order proponents like Aldous Huxley, who in his The Perennial Philosophy seeks to destroy the notion of a single Personal God, and thereby destroy the notion of personhood. Once the notion of personhood is gone as a metaphysical doctrine, it can be granted (and removed) at will via the apotheosized world-state. Yes, literally, by the pantheistic future world government. Huxley is quite candid about this, too. But all such attempts at deification of the state and destroying the biblical tradition are doomed to fail.
And so if there is in some sense a “perennial philosophy,” it is the perennial philosophy of the One True God, and not a pagan truth of generic, a-personal monotheism whereupon we can later attach the conception of a Personal deity, after we have borrowed bad arguments from Aristotle. We must begin with the Personal God who guides history by His providence. Only in this metaphysic do we have a grounded notion of person and protect the rights of the individual from the superstate-play-acting-as-God. We must then toss out the ‘traditionalists’ school of Coomaraswamy, Huxley and others, which really comes from Hinduism and is the sludge of the occult tradition passed down through the ages. The true perennial philosophy, then, as Justin points out (whether consistently or not) is the perennial philosophy of “Eyeh asher Eyeh.”