"If you found yourself at one of the seminars Ludwig Wittgenstein
(1889–1951) held in Cambridge in 1940 you would very quickly
realize that you were in the presence of someone very unusual.
Most people who met him thought he was a genius. Bertrand
Russell described him as ‘passionate, profound, intense and domi-
nating’. This small Viennese man with bright blue eyes and a deep
seriousness about him would pace up and down, asking students
questions, or pause lost in thought for minutes at a time. No one
dared interrupt. He didn’t lecture from prepared notes, but thought
through the issues in front of his audience, using a series of exam-
ples to tease out what was at stake. He told his students not to
waste their time reading philosophy books; if they took such
books seriously, he said, they should throw them across the room
and get on with thinking hard about the puzzles they raised."