Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Mu ammad ibn Mu ammad ibn al- asan al- s (born February 1201 in s, Khorasan 26 June 1274 in al-K imiyyah, Baghdad), better known as Na r al-D n al- s was a Persia polymath and prolific writer: an astronomer, biologist, chemist, mathematician, philosopher, physician, physicist, scientist, theologian and Marja Taqleed. He was of the Ismaili-, and subsequently Twelver Sh ah Islamic belief. The Arabian scholar Ibn Khaldun (1332-1406) considered Tusi to be the greatest of the later Persian scholars