Plotinus
Plotinus was a major philosopher of the ancient world. (204 AD - 270 AD)
Avicenna
commonly known as Ibn Sīnā, was a Persian polymath, who wrote almost 450 treatises on a wide range of subjects, of which around 240 have survived. In particular, 150 of his surviving treatises concentrate on philosophy and 40 of them concentrate on medicine. (980 AD - 1037 AD)