Mu'tazilism is an Islamic theological school of thought that emerged in the 8th century. It emphasizes reason and rationality in understanding faith, advocating that human intellect can discern moral truths. Mu'tazilites believe in the oneness of God, the justice of God, and the importance of free will, arguing that humans are responsible for their actions. The movement also engaged in debates about the nature of the Qur'an, asserting that it was created rather than eternal. This position led to significant theological discussions within the Islamic community, influencing later scholars and shaping Islamic philosophy.