Allogenes is a repertoire, or genre, of mystical Gnostic texts dating from the first half of the Third Century, CE. They concern Allogenes, "the Stranger" (or "foreigner"), a half-human, half-divine capable of communicating with realms beyond the sense-perceptible world, into the unknowable.
The Coptic text of Allogenes (Allog), the first Allogenes source to be discovered in modern times, is the third item in Codex XI of the Nag Hammadi library (NHC XI,3), held on leaves 45-69. The tops of many leaves are missing, as is the entire opening to the work.
The Temptation of Allogenes (Allogenes T), also in Coptic, is the fourth item in the Codex Tchacos, discovered in the 1970s but not made public until 2006. As this source also contains the text for the controversial Gospel of Judas, far more attention has been accorded to that work than to The Tempatation of Allogenes, which remains in a fragmentary condition. As one of the antiques dealers who handled Codex Tchacos disseminated parts of the manuscript for individual sale, not all of the pages relating to The Tempatation of Allogenes have been located, edited or published. An uncredited translation of part of the text from 2006 mixes up lines from The Gospel of Judas with passages from The Tempatation of Allogenes.
Radiocarbon dating establishes Codex Tchacos as physically earlier of the two sources, dating to 280 CE plus or minus sixty years. Nag Hammadi Codex IX, along with the rest of the library, dates from 348 CE plus or minus sixty years.
Writing between 374 and 375 CE in the "Against Sethians" section of his Panarion, also known as Against Heresies (39.5.1), Epiphanius of Salamis states that "[The Sethians] compose books in the names of great men, and say that seven books are in Seth's name, but give other, different books the name 'Stranger.'" Epiphanius comments that the Sethians "forged certain books in the name of Seth himself, and say they are given by him -- others in the name of him and his seven sons. For they say he had seven sons, called 'Strangers'". In 40.2.2 Epiphanius also mentions that the Archontics "have forged their own apocrypha (...) and by now they also have the ones called the 'Strangers.'"
No other Christian heresiologist of the ancient world mentions Allogenes, and based on this, Antoinette Clark Wire suggests that these works did not exist before 200 CE. However, more than a century before Epiphanius, the Allogenes books were likewise condemned by Neo-Platonist thinkers. In his Vita Plotini, Porphyry includes a list of texts known to Plotinus, which he describes as being written by "many Christians," containing entries for an Apocalypse of Allogenes in addition to one for Allogenes' son, Mesos. According to Zeke Mazur, the evaluation of this material at Rome by Plotinus' circle would have occurred in the 260s. Porphyry comments that "They deceived many, and were themselves deceived, as if Plato had not penetrated deeply into intelligible substance." Porphyry remembered that Plotinus delivered refutations to this literature in his lectures, and wrote a book, Against the Gnostics, which survives in the Enneads (II, 9) but Plotinus does not mention any particular book by name. Nevertheless, where Porphyry agrees with Epiphanius is that Allogenes was a cycle of books, referred to in the plural, rather than as a single work. No text corresponding to the Apocalypse of Mesos mentioned by Porphyry has ever been found.