Ibn Khaldun, the most celebrated thinker of the Muslim Middle Ages, is the subject of this intriguing study. Lacoste opens with a general description of the Maghreb in the later Middle Ages, focusing primarily on mercantile trade, especially in gold, and the social and economic structures of tribal life. He unravels Khaldun's fascinating biography--born of an aristocratic family in Tunis in 1332, he had an extraordinary diplomatic and military career in the turbulent wars and politics of Western Islam in the fourteenth century; withdrew to a desert retreat in 1375, and finally emigrated to...