h most important city in the world. It was the capital of a prosperous province called Khorassan. His family was Persian, and probably affluent, for he was given the best education available. At his university the dominant philosophy seems to have been that sophisticated meld of Platonic and Aristotelian ideas elaborated by the Persian scholar Avicenna during the previous generation. But other influences were present as well. One of his biographers notes: "In that province of Khorassan where Omar was born, followers of the Buddha ... had for centuries existed."2 Significant also was the presence of the Brothers of Purity, a group of philosophers similar to the French Encyclopedists of a much later era. These scholars "conducted their speculations on a materialistic plain and attacked all problems with the instrument of human understanding. They had a bias to natural science and tried to found a philosophy on its discoveries.3
             Omar lived from 1048 to 1131. During the decades preceding his birth, Turkish tribes had been steadily encroaching on the se
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