(March 3, 2025) While dualism started innocently enough it has become one of the great curses of humanity amplifying the "us versus them" mentality. Dualism was an idea by a Pagan Persian priest called Zoroaster (by the Greeks). He observed that conscious experiences like smells were inherently good or bad. Therefore the divine realm was also inherently good or bad. (this assumption of inherent valuation of conscious experiences was only proved false in modern times by neuroscience).
Zoroastrianism claimed these two realms were at war with each other until the end times when they would be united once again. Zoroastrianism was adopted as the religion of the Persian Achaemenid Empire (550-330 BCE) because this ideology ended up supporting empires. Their kings could portray themselves as the good guys fighting the evil other. The resulting empire spread dualism far and wide. This is also why Roman Emperor Constantine (306 to 337 CE) adopted it in its Christian form and why his successors forced it onto the Roman empire.
In the west, idea was inserted into Judaism and from there into Christianity and Islam. In the east it triggered the debates which led to the founding of Buddhism as a dualist religion whose followers seek to escape the imperfect material world. Buddhism in turn led to the counter ideology of Hinduism seen in the Bhagavad Gita which is a statement against the impossibility of defining absolute evil.
Mainstream classical culture also became dualist with its traditional nature based spirituality (Pythagorean, Orcus in classical times) being replaced by Stoicism. The anti-dualist reaction against Stoicism was Epicureanism and Skepticism (305 BCE and after) with its teaching that pleasure is not evil.
(July 3, 2022, updated March 17, 2025) Dualism within its conscious feeling context is first detected in the earliest Zoroastrian scriptures (Yasnas) known as the Gathas where Spenta Manyu (community supporter) is at odds with the Angra Manyu meaning “Anger supporter.” Anger is a conscious feeling. Also notice the perceptheism here in which divine powers are personified.
Yet Zoroaster did not really like the consequences of his dualism because it meant splitting the Divine realm into Good and Evil halves at war with each other. Thus he came up with the end times idea which would reunite the two halves into an eternal whole:
Because Zoroastrianism was lordified it separated divine powers into spirits and personified gods and goddesses. The spirits of nature, the daevas now became evil because they could not discern between Good and Evil. The religious culture of Zoroaster was fully lordified with the result that Divine powers were now thought of as impersonal spirits instead of as deity which could be optionally personified. This word became “devils” in English. As shown below, all those who follow Evil powers (druj) were to be killed and those doing the killing will be favored by lord Mazda.
Yet Good thoughts can also lead to the kingdom (dominion) of God (Ahura Mazda) on earth. Jesus seems to adopted this idea without the dualism: