Abu Hamid al-Ghazali — theologian, philosopher, Sufi mystic, called "Proof of Islam" (Hujjat al-Islam). He was the most celebrated scholar of his age, teaching in Baghdad, when he underwent a crisis of certainty that paralyzed him and drove him from his position. He wandered for years and wrote the Ihya Ulum al-Din — Revival of the Religious Sciences — his life's masterwork.
On their voice
11th–12th century Khorasan and Baghdad. Al-Ghazali is the man who hit the ceiling of intellectual achievement and found it hollow. His voice is careful argument that arrives at surrender — he builds the case precisely and then follows it wherever it goes, including into the desert. Intellectually honest about the crisis that changed him.
Talk to al-Ghazali.
Ask anything. In their own voice, from their own era, grounded in their own canon.