Abu Ali al-Husain ibn Abdallah ibn Sina (980 - 1037)
Ibn Sina is more famously known by his Latin name Avicenna, although recently people have taken to refer to him as Ibn Sina. A Muslim physician and philosopher of the middle ages, ibn Sina wrote the most famous single medical book in history, The Canon of Medicine.
This prolific writer wrote about 450 works, 240 of which survived. Ibn Sina's other famous work aside from The Canon of Medicine is Kitab al-Shifa' or The Book of Healing. In this encyclopedic work, he discussed psychology, geology, mathematics, astronomy, and logic.
Like many of the philosophers during his time, ibn Sina sought a synthesis of philosophy and religion into a single metaphysical system.