In Our Time discussed the 9th century physician and philosopher Avicenna. I had heard of his name, but knew hardly more than that through his writings Aristotle made it to the West in the Renaissance. What I did not know, was that he wrote comments on Aristotle, so influential, that until his age, one commented on Aristotle and after him, one commented on Avicenna's works, among which, his comments on Aristotle.
Should one think influential philosophers are isolated and ascetic figures such as Kant, with Avicenna the picture turns out completely different. He was flamboyant, traveled extensively and indulged in wine and sex. Where his student and biographer praises Avicenna's prowess in carnal activities, Avicenna himself, so it turns out in the beginning of the show, praises himself for his genius. He seems to be able to pull the inflated ego off and is considered among the most influential thinkers of the Middle Ages.
In fact, he is the first thinker of whom I know he has put his mark on Islam (directly) as well as Judaism and Christianity. It is said his works were an inspiration for Maimonides (Rambam) and for Thomas Aquinas. Listen to Melvyn Bragg's guests explain this feat.