Aristocritus (Ancient Greek: Ἀριστόκριτος) was a Christian, Platonist writer of the fifth century who was the author of a work titled Theosophy, ostensibly about oracles, but in which he expressed a controversial syncretic belief that Christianity, Judaism, and Manichaeism were all basically the same.
[1][2] This belief caused him to be condemned by Zacharias Rhetor as well as in various later Byzantine texts.
[3] He is known to us primarily by his mention in a list of medieval anathemas, written around the year 1000, known as the Long Anathema, primarily aimed at Manichaeans.
His identification as a Manichaean is however considered somewhat dubious, as he was known to write uncharitable things about Mani himself.
[4] Theosophy is a lost work, though some scholars have identified this with the so-called Theosophy of Tübingen.