The philosopher trained his brain to make smarter decisions. The comedian learned to laugh at himself. Informed doubt was the secret. — It’s not so much knowing when to speak, but when to pause. If René Descartes saw Jack Benny strolling the Rue de Rivoli, he would ask, "Do you speak Latin?" On cue, Benny would do a double take and declare, "Why certainly, I speak Latin," followed by a lengthy pause…