linguistic:translation, structural:scholar_edition
In classical antiquity

The Greeks—in the Hellenistic sense of the term—had an understanding of Zoroaster as expressed by Plutarch, Diogenes Laertius, and Agathias that saw him, at the core, to be the "prophet and founder of the religion of the Iranian peoples," Beck notes that "the rest was mostly fantasy". Zoroaster was set in the ancient past, six to seven millennia before the Common Era, and was described as a king of Bactria or a Babylonian (or teacher of Babylonians), and with a biography typical of a Neopythagorean sage, i.e. having a mission preceded by ascetic withdrawal and enlightenment. However, at first mentioned in the context of dualism, in Moralia, Plutarch presents Zoroaster as "Zaratras," not realizing the two to be the same, and he is described as a "teacher of Pythagoras ".

Zoroaster has also been described as a sorcerer-astrologer – the creator of both magic and astrology. Deriving from that image, and reinforcing it, was a "mass of literature" attributed to him and that circulated the Mediterranean world from the 3rd century BC to the end of antiquity and beyond.

The language of that literature was predominantly Greek, though at one stage or another various parts of it passed through Aramaic, Syriac, Coptic, or Latin. Its ethos and cultural matrix was likewise Hellenistic, and "the ascription of literature to sources beyond that political, cultural and temporal framework represents a bid for authority and a fount of legitimizing "alien wisdom". Zoroaster and the magi did not compose it, but their names sanctioned it." The attributions to "exotic" names (not restricted to magians) conferred an "authority of a remote and revelatory wisdom."

Among the named works attributed to "Zoroaster" is a treatise On Nature (Peri physeos), which appears to have originally constituted four volumes (i.e. papyrus rolls). The framework is a retelling of Plato's Myth of Er, with Zoroaster taking the place of the original hero. While Porphyry imagined Pythagoras listening to Zoroaster's discourse, On Nature has the Sun in middle position, which was how it was understood in the 3rd century. In contrast, Plato's 4th-century BC version had the Sun in second place above the Moon. Colotes accused Plato of plagiarizing Zoroaster, and Heraclides Ponticus wrote a text titled Zoroaster based on his perception of "Zoroastrian" philosophy, in order to express his disagreement with Plato on natural philosophy. With respect to substance and content in On Nature only two facts are known: that it was crammed with astrological speculations, and that Necessity (Ananké) was mentioned by name and that she was in the air.

Pliny the Elder names Zoroaster as the inventor of magic (Natural History 30.2.3). "However, a principle of the division of labor appears to have spared Zoroaster most of the responsibility for introducing the dark arts to the Greek and Roman worlds." That "dubious honor" went to the "fabulous magus, Ostanes, to whom most of the pseudepigraphic magical literature was attributed." Although Pliny calls him the inventor of magic, the Roman does not provide a "magician's persona" for him. Moreover, the little "magical" teaching that is ascribed to Zoroaster is actually very late, with the very earliest example being from the 14th century.

Association with astrology according to Roger Beck, were based on his Babylonian origin, and Zoroaster's Greek name was identified at first with star-worshiping (astrothytes, 'star sacrificer") and, with the Zo-, even as the 'living' star. Later, an even more elaborate mythoetymology evolved: Zoroaster died by the living (zo-) flux (ro-) of fire from the star (astr-) which he himself had invoked, and even, that the stars killed him in revenge for having been restrained by him.

The alternate Greek name for Zoroaster was Zaratras or Zaratas/Zaradas/Zaratos. Pythagoreans considered the mathematicians to have studied with Zoroaster in Babylonia. Lydus, in On the Months, attributes the creation of the seven-day week to "the Babylonians in the circle of Zoroaster and Hystaspes," and who did so because there were seven planets. Lucian of Samosata, in Mennipus 6, reports deciding to journey to Babylon "to ask one of the magi, Zoroaster's disciples and successors," for their opinion.

While the division along the lines of Zoroaster/astrology and Ostanes/magic is an "oversimplification, the descriptions do at least indicate what the works are not "; they were not expressions of Zoroastrian doctrine, they were not even expressions of what the Greeks and Romans " imagined the doctrines of Zoroastrianism to have been". The assembled fragments do not even show noticeable commonality of outlook and teaching among the several authors who wrote under each name.

Almost all Zoroastrian pseudepigrapha is now lost, and of the attested texts—with only one exception—only fragments have survived. Pliny's 2nd- or 3rd-century attribution of "two million lines" to Zoroaster suggest that (even if exaggeration and duplicates are taken into consideration) a formidable pseudepigraphic corpus once existed at the Library of Alexandria. This corpus can safely be assumed to be pseudepigrapha because no one before Pliny refers to literature by "Zoroaster", and on the authority of the 2nd-century Galen of Pergamon and from a 6th-century commentator on Aristotle it is known that the acquisition policies of well-endowed royal libraries created a market for fabricating manuscripts of famous and ancient authors.

The exception to the fragmentary evidence (i.e. reiteration of passages in works of other authors) is a complete Coptic tractate titled Zostrianos (after the first-person narrator) discovered in the Nag Hammadi library in 1945. A three-line cryptogram in the colophones following the 131-page treatise identify the work as "words of truth of Zostrianos. God of Truth. Words of Zoroaster." Invoking a "God of Truth" might seem Zoroastrian, but there is otherwise "nothing noticeably Zoroastrian" about the text and "in content, style, ethos and intention, its affinities are entirely with the congeners among the Gnostic tractates."

Another work circulating under the name of "Zoroaster" was the Asteroskopita (or Apotelesmatika), and which ran to five volumes (i.e. papyrus rolls). The title and fragments suggest that it was an astrological handbook, "albeit a very varied one, for the making of predictions." A third text attributed to Zoroaster is On Virtue of Stones (Peri lithon timion), of which nothing is known other than its extent (one volume) and that pseudo-Zoroaster 'sang' it (from which Cumont and Bidez conclude that it was in verse). Numerous other fragments preserved in the works of other authors are attributed to "Zoroaster", but the titles of those books are not mentioned.

These pseudepigraphic texts aside, some authors did draw on a few genuinely Zoroastrian ideas. The Oracles of Hystaspes, by " Hystaspes ", another prominent magian pseudo-author, is a set of prophecies distinguished from other Zoroastrian pseudepigrapha in that it draws on real Zoroastrian sources. Some allusions are more difficult to assess: in the same text that attributes the invention of magic to Zoroaster, Pliny states that Zoroaster laughed on the day of his birth, although in an earlier place, Pliny had sworn in the name of Hercules that no child had ever done so before the 40th day from his birth. This notion of Zoroaster's laughter also appears in the 9th– to 11th-century texts of genuine Zoroastrian tradition, and for a time it was assumed that the origin of those myths lay with indigenous sources. Pliny also records that Zoroaster's head had pulsated so strongly that it repelled the hand when laid upon it, a presage of his future wisdom. The Iranians were however just as familiar with the Greek writers, and the provenance of other descriptions are clear. For instance, Plutarch's description of its dualistic theologies reads thus: "Others call the better of these a god and his rival a daemon, as, for example, Zoroaster the Magus, who lived, so they record, five thousand years before the siege of Troy. He used to call the one Horomazes and the other Areimanius ".