Na~ir aI-Din, known to his compatriots as Mu}:taqqiq-i Tiisi, Khwiija-yi Tiisi, or Khwiijah Na~ir, (1201-1274) is one of the best-known and most influential figures in Islamic intellectual history. He studied the religious sciences and elements of the "intellectual sciences" with his father, a jurisprudent of the Twelve Imam school of Shi 'ism at Tiisi He also very likely studied logic, natural philosophy, and metaphysics with his maternal uncle in the same city. During this period he also received instruction in algebra and geometry. Afterward he set out for N aishapur, then still a major center of learning, to complete his formal advanced education; and it was in this city that he gained a reputation as an outstanding scholar. His most famous teachers were Fand aI-Din aIDamad, who through four intermediaries was linked to Ibn Slna and his school and with whom Tiisi studied philosophy; Qutb aI-Din al-Mi~n, who was himself the best known student of Fakhr aI-Din al-Riizl (11481209), with whom Tiisi studied medicine, concentrating mostly on the textofIbn Sinii's Canon; and Kamiilal-Dinibn Yiinus (1156-1242), with whom he studied mostly mathematics.