Adams gives Oriental Philosophy a full entry of its own, and it is the richest single node of the reservoir in her dictionary. The oriental philosophers, she reports following Enfield and Mosheim, explained the origin of all things by emanation from an eternal fountain of being, a system whose reduction to order she attributes to Zoroaster: spirit and matter, light and darkness, flowing from one source, with the human soul a particle of divine light bound to return to it and matter the last and most distant emanation, opaque, inert, and the cause of evil until it too is refined back into the fountain.
She then sets that system inside the history of the ancient theology. At the time of Christ two philosophies stood in the field, the Greek and the Oriental, and the adherents of the latter claimed to be restorers of a knowledge of God that the world had lost, which is why the archive reads it as a reservoir rather than a sect. Taught in the east before the Christian era, it spread through the Alexandrian, Jewish, and Christian schools, split into three sects over the origin of matter and evil, and, blended with Christianity, gave rise to the Gnostic sects of the first centuries.
The cross-references carry the thread further. The Gnostics, she notes, derived their origin from the oriental philosophy, and the pre-existence of the soul was the great doctrine of the eastern sages from time immemorial; those same sages expected an extraordinary messenger of the Most High sent to restore the knowledge of the Supreme Being; and Ammonius at Alexandria built a creed that was a mixture of Christianity and oriental philosophy. That genealogy, from an eastern emanationist source down into Gnosticism and the Alexandrian schools, is the eighteenth-century framing the archive is tracing across the reservoir.
In Hannah Adams
In Adams’s own words, from the 1817 Dictionary. Each passage is quoted verbatim under its own entry.
ORIENTAL PHILOSOPHY. The oriental philosophers endeavoured to explain the nature and origin of all things, by the principle of emanation from an eternal fountain of being. The formation of this philosophy into a regular system has been attributed to Zoroaster, an ancient Persian philosopher, who adopted the principle, generally held by the ancients, that “from 'nothing nothing can be produced.” He supposed spirit and matter, light and darkness, to be emanations from one eternal source. The active and passive principles he conceived to be perpetually at variance; the former tending to produce good, the latter, evil: but that through the intervention of the supreme Being the contest would at last terminate in favour of the good principle. According to Zoroaster, various orders of spiritual beings, gods, or demons, have proceeded from the Deity, which are more or less perfect, as they are at a greater or less distance, in the course of emanation, from the eternal fountain of intelligence; among those, the human soul is a particle of divine light, which will return to its source and partake of its immortality: and matter f Lardner’s Heretics, p. 352: is the last, or most distant emanation from the first source of being, which, on account of its distance from the fountain of light, becomes opaque and inert, and whilst it remains in that state is the cause of evil: but, being gradually refined, it will at last return to the fountain from whence it flowed.
Hannah Adams, A Dictionary of All Religions and Religious Denominations, 4th ed. (Boston: Cummings and Hilliard, 1817), entry “Oriental Philosophy” (pp. 210–211).