Zoroaster (Zarathushtra Spitama) was an ancient Iranian religious reformer and philosopher who laid the foundations of Zoroastrianism. While his exact lifetime remains a subject of intense scholarly debate, linguistic analysis of the Gathas—the oldest hymns traditionally attributed to him—suggests they were composed around 1000 BCE.

At the core of Zoroastrian philosophy lies a profound cosmic and ethical dualism. The universe is conceptualized as a battleground between 'Asha' (truth, cosmic order, and righteousness) and 'Druj' (chaos, deceit, and destruction). In this system, Ahura Mazda is the supreme creator and the source of all goodness. Humans are endowed with free will and are active participants in this cosmic struggle, called to align themselves with truth through good thoughts (Humata), good words (Hukhta), and good deeds (Hvarshta).

This moral dualism translated the battle between good and evil into a universal framework, influencing later Greek philosophers like Heraclitus and Plato. It also played a seminal role in shaping key theological concepts—such as personal eschatology, free will, and a linear struggle between good and evil—in major Abrahamic religions, including Judaism, Christianity, and Islam.