Ibn Sina

Ibn Sina, known in Europe as Avicenna, wrote The Canon of Medicine around 1025, a five volume systemization of Greek, Indian and Islamic medical knowledge that set out rules for testing a drug's effect: try it on an uncomplicated case, observe the same result across repeated trials, and rule out other causes before crediting the drug. The Canon remained a standard medical textbook in European universities into the seventeenth century. He also wrote extensively on logic and metaphysics, and served as a court physician and administrator across several Persian and Central Asian courts.