They're bearded, therefore... (updated)

Do you know any 'great beards in philosophy'? The Faculty of Philosophy at the University of Cambridge has this collection (scroll down), and asks if they're missing any. (Thanks: D.)

I'll offer Ludwig Feuerbach's beard. I think it's good enough, don't you? But always remember: a beard does not a philosopher make.

Update at 2.00 PM: Chris at the Stoa has information on the origins of the connection between philosophers and beards.