is it me or does the 4th philosopher from the left up there ^^^ look like pete postlethwaite?
not really, but the first one looks like the bloke who plays billy in eastenders. crazy. excuse my ignorance, but who are those men anyway?
from left to right, ludwig wittgenstein (author of the Tractatus Logico Philosophicus and his later work Philosophical Investigations). Frederick Nietszche, famous for having said “God is dead”. Karl Marx, you probably know about him. Bertran Russell, more contemporary philosophy (now dead), wrote “A history of western philosophy” and finally we have Socrates, a pioneer of philosophy who said “i know that i know nothing”.
yay Marx, famous for Das Kaptial
“yay marx”?
Back to your shed, boy 
“I know I know nothing”… bit of an idiot then? 
I know I know something buddy
The British comedy actor version.
From left to right: Rob Brydon from Marion & Jeff, Uncle Albert from Only Fools and Horses, Brian Blessed, Paul Eddington from Yes Prime Minister, Del Boy from Only Fools and Horses again.
OK, so the last one was scraping the barrel a little.