The root of all Western esotericism is Zoroastrianism/Zurvanite thought
Let's roll back the clock to the ancient days of Persian Zoroastrianism. This was a sharply dualistic religion, postulating a pure battle between good and evil for all eternity, in a kind of dynamic flux/balance. The Persians conquered the Babylonians and over time their cultures mixed to some extent. The Babylonians had many gods, as well as deep astronomical/astrological knowledge and theology. One result of the mixing of Persian and Babylonian ideas was Zurvanism, a "heretical" form of Zoroastrianism that postulated a higher god over the realms of good and evil. In this view, good and evil were not the supreme forces but rather "brothers" spawned by a higher god, Time itself. These people also had and protected very advanced ideas about astronomy and astrology, much of which was encoded in myth as allegories and mynomics. This offshoot of more orthodox Zoroastrianism eventually spread west in a kind of corrupted form through trade and the general drift of time, as well as more direct contact through various wars and so on. This resulted in the Roman "mystery religion" of Mithraim. This is not a pure form of Zurvanism but rather involves Zurvanite elements fused with other esoteric ideas floating around at the time. In Mithraism, the central image is a man killing a bull. There is an ancient Zoroastrian belief about the evil god killing a bull, but he was "inverted" into a heroic figure through Mithraism, perhaps representing the way Zoroastrian ideas of "pure evil" were transcended by a "higher" zurvanite God. The idea of the death of the bull also had a more esoteric astrological meaning: the change from the astrological age of Taurus the Bull to the age of Aries the Ram. Other astrological imagery surrounds Mithraic art...too complex to go into here, but full of images of the night sky in the form of beasts like snakes (constellation draco), scorpions (scorpio) and so on. Mithraism also took some ideas from early Jewish mysticism, like Merkabah mysticism where one ascended through various "halls" or levels to become purified. Mithraism was a very popular cult in the late Roman Empire and one of the main competitors of early Christianity. The ultimate dominance of Christianity prtetty much destroyed Mithraism, while in the east, Islam overran the final scraps of Zurvanite thought. Both these religions seemed to disappear from the earth, but actually Mithraic ideas and imagery remaind strong in the west, in the form of Astrology and other esoteric arts (alchemy, "high magic," etc.) So that's how it all breaks down... Zoroastrianism, Mithraism, Manicheism are the roots of one side of the Western esotericism, i.e. that part which become monotheists religions such as judaism, islam and christianism. The other side of western esotericism is a reminisnence of the shamanism, which first came from the east (Siberia, India) and was still represented by the antic mysteries (Dyonisiac mysteries, paganism, feminity cults). One side is paternalistic (zoroastrism) while the other is maternalistic (feminity cults). Both always coexisted, fighted each other, and tried to shape the cultures through the ages. Today they still exists under various forms. Paternalistic : religions (Islam, Judaism, Catholic Church, ...), autoritarian/supranational governments, liberal economy, ... Maternalistic : new age movements, ecology, local governments, exchange-based economy, The esotericism, just like our different cultures, were always two-sided like Janus. This is what allowed us to always evolve, exchange views, and never become stuck in a single cultural mindset. oriental cultures understood that and described it via the Yin and Yang. But it is an universal truth that we tend to forget. There will ALWAYS be opposite because that is what make life possible. Opposite create dynamism. Hot and cold create exchange Up and down create movement Male and female create life Paternalistic and Maternalistic esotericism create cultures. Also Zoroastrianism wasn't completely crushed by christianism, it was continued via Gnosticism, which as you said also influenced alchemy and astronomy. On the other hand, Mithraism definitily influenced christianism, islam etc, because it was a messianic cult. We both now that there are still very large messianic "cults" (I should say religion) alive today. So the Mithraism never really disappeared. A fun fact from Zoroastrianism : For that cult, when you die, the appropriate way to dispose of your corpse is not to be buried or burned, but to be exposed to desert sun, on a large stone surfarce, and offered to the appetite of the vutlures.
Let's roll back the clock to the ancient days of Persian Zoroastrianism. This was a sharply dualistic religion, postulating a pure battle between good and evil for all eternity, in a kind of dynamic flux/balance. The Persians conquered the Babylonians and over time their cultures mixed to some extent. The Babylonians had many gods, as well as deep astronomical/astrological knowledge and theology. One result of the mixing of Persian and Babylonian ideas was Zurvanism, a "heretical" form of Zoroastrianism that postulated a higher god over the realms of good and evil. In this view, good and evil were not the supreme forces but rather "brothers" spawned by a higher god, Time itself. These people also had and protected very advanced ideas about astronomy and astrology, much of which was encoded in myth as allegories and mynomics. This offshoot of more orthodox Zoroastrianism eventually spread west in a kind of corrupted form through trade and the general drift of time, as well as more direct contact through various wars and so on. This resulted in the Roman "mystery religion" of Mithraim. This is not a pure form of Zurvanism but rather involves Zurvanite elements fused with other esoteric ideas floating around at the time. In Mithraism, the central image is a man killing a bull. There is an ancient Zoroastrian belief about the evil god killing a bull, but he was "inverted" into a heroic figure through Mithraism, perhaps representing the way Zoroastrian ideas of "pure evil" were transcended by a "higher" zurvanite God. The idea of the death of the bull also had a more esoteric astrological meaning: the change from the astrological age of Taurus the Bull to the age of Aries the Ram. Other astrological imagery surrounds Mithraic art...too complex to go into here, but full of images of the night sky in the form of beasts like snakes (constellation draco), scorpions (scorpio) and so on. Mithraism also took some ideas from early Jewish mysticism, like Merkabah mysticism where one ascended through various "halls" or levels to become purified. Mithraism was a very popular cult in the late Roman Empire and one of the main competitors of early Christianity. The ultimate dominance of Christianity prtetty much destroyed Mithraism, while in the east, Islam overran the final scraps of Zurvanite thought. Both these religions seemed to disappear from the earth, but actually Mithraic ideas and imagery remaind strong in the west, in the form of Astrology and other esoteric arts (alchemy, "high magic," etc.) So that's how it all breaks down... Zoroastrianism, Mithraism, Manicheism are the roots of one side of the Western esotericism, i.e. that part which become monotheists religions such as judaism, islam and christianism. The other side of western esotericism is a reminisnence of the shamanism, which first came from the east (Siberia, India) and was still represented by the antic mysteries (Dyonisiac mysteries, paganism, feminity cults). One side is paternalistic (zoroastrism) while the other is maternalistic (feminity cults). Both always coexisted, fighted each other, and tried to shape the cultures through the ages. Today they still exists under various forms. Paternalistic : religions (Islam, Judaism, Catholic Church, ...), autoritarian/supranational governments, liberal economy, ... Maternalistic : new age movements, ecology, local governments, exchange-based economy, The esotericism, just like our different cultures, were always two-sided like Janus. This is what allowed us to always evolve, exchange views, and never become stuck in a single cultural mindset. oriental cultures understood that and described it via the Yin and Yang. But it is an universal truth that we tend to forget. There will ALWAYS be opposite because that is what make life possible. Opposite create dynamism. Hot and cold create exchange Up and down create movement Male and female create life Paternalistic and Maternalistic esotericism create cultures. Also Zoroastrianism wasn't completely crushed by christianism, it was continued via Gnosticism, which as you said also influenced alchemy and astronomy. On the other hand, Mithraism definitily influenced christianism, islam etc, because it was a messianic cult. We both now that there are still very large messianic "cults" (I should say religion) alive today. So the Mithraism never really disappeared. A fun fact from Zoroastrianism : For that cult, when you die, the appropriate way to dispose of your corpse is not to be buried or burned, but to be exposed to desert sun, on a large stone surfarce, and offered to the appetite of the vutlures.