Avicena(Ibn Sina)
(980-1037) Spain. Writer

Islamic philosopher and physician author of the brilliant Commentaries to the work of Aristotle as well as Canons of Medicine - which became indispensable in western universities - and other encyclopedic works. He became interested in the relationship between the beign and its essence and between the possible and the necessary. God is the necessary being where essence and existence merge. His thoughts provoqued interesting debates during the Middle Ages and the Renaissance.