The Persian jurist, theologian, and mystic who, at the height of his fame, abandoned a prestigious teaching post in Baghdad for a decade of withdrawal — and whose two greatest works, a sharp critique of the Aristotelian philosophers and a vast synthesis of law with Sufi spirituality, reshaped mainstream Sunni Islam, making mysticism respectable and setting the terms on which faith and reason would be argued for centuries.
At the height of his fame, Abu Hamid al-Ghazali could not speak. He held the most prestigious teaching chair in the Islamic world, in Baghdad, with hundreds of students hanging on his words. Then, by his own later account, his tongue seized up in the lecture hall. He could no longer eat or teach. Doctors found no bodily cause. He gave away his wealth, left the city on the pretext of pilgrimage, and disappeared from public life for roughly a decade. The man who walked away was one of the most celebrated scholars of his age. What he wrote afterward changed how Muslims have understood the relationship between knowledge, doubt, and God ever since.