Book excerpt: The very heart of the Islamic tradition is love; no other word adequately captures the quest for transformation that lies at this tradition's center. So argues esteemed professor of medieval Islam William C. Chittick in this survey of the extensive Arabic and Persian literature on topics ranging from the Qur'an up through the twelfth century. Bringing to light extensive foundational Persian sources never before presented, Chittick draws on more than a thousand pages of newly translated material to depict the rich prose literature at the center of Islamic thought.