Mu'tazilism

Mu'tazilism is a school of Islamic theology (kalam) that emerged in Basra in the early eighth century CE, traditionally traced to Wasil ibn Ata, and that insisted reason and revelation could never genuinely conflict, so that rational argument was a legitimate and necessary tool for establishing theological truth rather than a threat to it. Its five defining principles held God's absolute unity (tawhid) to require that divine attributes not be treated as eternal entities alongside God, affirmed human free will and responsibility for action against strict predestination, and held that God's justice (adl) obliges God to reward good and punish evil according to rational standards of fairness. Under Abbasid patronage the school briefly became state orthodoxy during the mihna inquisition of the ninth century, when scholars including Ahmad ibn Hanbal were pressured to accept its doctrine that the Quran was created rather than eternal, a controversy that provoked lasting backlash. Mu'tazilite rationalism was eventually eclipsed as mainstream Sunni orthodoxy by the rise of Ash'arism, though its arguments continued to shape later Islamic philosophy and found lasting influence among Twelver Shi'a and Zaydi theology.