Four Quarters, Written After Walking Away From a Prestigious Post

The Ihya Ulum al-Din, the Revival of the Religious Sciences, is Abu Hamid al-Ghazali's vast systematic treatise on Islamic spiritual and ethical life, organized into four quarters covering the outward acts of worship, the norms of everyday social conduct, the vices that destroy the soul, and the virtues that save it, moving a reader step by step from external observance toward inner transformation.

Al-Ghazali composed it after abandoning his prestigious teaching post at the Nizamiyya college in Baghdad around 1095, following what he described as a personal crisis of certainty that led him first into skepticism and then into a period of withdrawal and Sufi practice, an experience the Ihya draws on directly even as it remains a work of systematic instruction rather than autobiography. The book deliberately builds a bridge between the outward legal and theological sciences that dominated mainstream Sunni scholarship and the inward disciplines of Sufism, which many jurists of al-Ghazali's time regarded with suspicion, arguing at length that the two are not in competition but that correct outward practice is empty without the inward states the Sufis cultivated. Each of the four quarters is itself further subdivided into ten books, giving the whole work a scale closer to an encyclopaedia than to a single treatise.