Abu Ali al - Husain ibn Abdallah ibn Sina (Avicenna)

Born: 980 in Kharmaithen (near Bukhara), Central Asia (now Uzbekistan)

Ibn Sina or Avicenna was the most influential of all Islamic philosopher - scientists. He wrote on medicine as well as geometry, astronomy, arithmetic and music. Ibn Sina's two most important works are The Book of Healing and The Canon of Medicine. The first is a scientific encyclopaedia covering logic, natural sciences, psychology, geometry, astronomy, arithmetic and music. The second is the most famous single book in the history of medicine.

Ibn Sina wrote about 450 works, of which around 240 have survived. Of the surviving works, 150 are on philosophy while 40 are devoted to medicine, the two fields in which he contributed most. He also wrote on psychology, geology, mathematics, astronomy, and logic. His most important work as far as mathematics is concerned, however, is his immense encyclopaedic work, the Kitab al - Shifa (The Book of Healing). One of the four parts of this work is devoted to mathematics and ibn Sina includes astronomy and music as branches of mathematics within the encyclopaedia. In fact he divided mathematics into four branches, geometry, astronomy, arithmetic, and music, and he then subdivided each of these topics. Geometry he subdivided into geodesy, statics, kinematics, hydrostatics, and optics; astronomy he subdivided into astronomical and geographical tables, and the calendar; arithmetic he subdivided into algebra, and Indian addition and subtraction; music he subdivided into musical instruments.