Avicenna

Ibn Sina, known in the West as Avicenna, was a Persian polymath — philosopher, physician, mathematician, and scientist — whose influence on both Islamic and European thought was immense. His philosophical encyclopedia, the Shifa, synthesised Aristotelian and Neoplatonic philosophy with Islamic theology, and his Canon of Medicine remained a standard medical textbook in Europe for centuries. His "floating man" thought experiment anticipates Descartes's cogito by six centuries.