I claim that the thinker on the picture above had far more lasting and powerful impact on the human minds of the XXth and XXIth century than minor figures like Marx, Hitler, Freud, Mao, Lennon, Lenin, Hawking, Chomsky and Michael Jackson.
What, you do not RECOGNIZE HIM?
Tip Nr. 1: He hailed from the same city as the guy who invented this bloody chess opening.
1. d2-d4 d7-d5 . 2. c2-c4 e7-e6 3. Kb1-c3 c7-c5
Tip Nr. 2: In case you still do not recall him or do not identify the appearance with the name: probably you suffer from the condition described by this guy!