Zoroaster, also known as Zarathustra, was an ancient Iranian religious teacher and prophet traditionally regarded as the founder of Zoroastrianism. The exact dates of his life are uncertain and remain debated by scholars, with estimates ranging from the second millennium BCE to around the 6th century BCE. Zoroaster is believed to have lived in eastern Iran or Central Asia, within a cultural environment shaped by early Indo-Iranian religious traditions.
Zoroaster is credited with reforming earlier religious practices through a new ethical and theological vision. Central to his teaching was the worship of Ahura Mazda, the supreme and wise creator deity. Zoroaster presented Ahura Mazda as the source of truth, order, and goodness, rejecting the ritualistic polytheism common in earlier traditions. His teachings were conveyed through hymns known as the Gathas, which form the oldest and most important part of the Zoroastrian sacred texts, the Avesta.
A key feature of Zoroaster’s thought is ethical dualism. He described the universe as a moral battleground between opposing principles: asha (truth, order, and righteousness) and druj (falsehood and chaos). Human beings play an active role in this struggle through their choices and actions. Zoroaster emphasised individual responsibility, teaching that each person must choose between good and evil through good thoughts, good words, and good deeds.
Zoroaster also introduced a distinctive understanding of time and history. He taught that the world moves toward a final resolution in which good ultimately triumphs over evil. This idea included concepts of judgement, moral accountability, and the renewal of the world. These themes later influenced other religious traditions, particularly Judaism, Christianity, and Islam, during periods of cultural contact in the ancient Near East.
Ritual practice in Zoroastrianism developed after Zoroaster’s lifetime but reflects his emphasis on purity and order. Fire came to symbolise divine truth and wisdom rather than being worshipped directly. Zoroastrian temples preserved sacred fires as representations of Ahura Mazda’s light and presence. The religion also placed importance on maintaining purity in daily life, especially in relation to the natural elements.
Zoroastrianism became closely associated with Persian imperial culture, particularly under the Achaemenid and later Sasanian empires. Although it declined after the Islamic conquest of Persia, Zoroastrian communities survived in Iran and later in India, where the Parsis preserved religious traditions and texts.
Zoroaster remains a historically significant figure for introducing one of the earliest ethical monotheistic systems. His teachings shaped religious thought across a wide geographical area and contributed enduring ideas about morality, cosmic order, and human responsibility within the history of religion and philosophy.