al-Ghazālī

Abū Ḥāmid al-Ghazālī was born around 1058 at Ṭūs, in Khurasan, in northeastern Iran. He studied law and theology at Nishapur under al-Juwaynī, and in 1091 the vizier Niẓām al-Mulk appointed him to teach at the Niẓāmiyya college in Baghdad, the most prestigious post of its kind. There he wrote on law and theology and studied the philosophers, attacking them in The Incoherence of the Philosophers.

Around 1095 he suffered a crisis, which he later described in his autobiography, Deliverance from Error: doubt about the certainty of his knowledge, and the conviction that his teaching was driven by love of fame. He lost the ability to speak and teach, left Baghdad, and for about ten years lived as a Sufi, in Damascus, Jerusalem and Mecca, before returning to Ṭūs. He taught again briefly at Nishapur, and died at Ṭūs in 1111.

His great work, The Revival of the Religious Sciences, brought Sufi inwardness into the mainstream of Islamic law and devotion, and his authority did much to make Sufism respectable. He has been called the most influential Muslim after the Prophet, a judgment often repeated and debated.