Cogito cogito ergo cogito sum -- "I think that I think, therefore I think that I am;" as close an approach to certainty as any philosopher has yet made.
Ambrose BierceInventor: A person who makes an ingenious arrangement of wheels, levers and springs, and believes it civilization.
Ambrose Bierceoptimism, n. The doctrine, or belief, that everything is beautiful, including what is ugly, everything good, especially the bad, and everything right that is wrong. It is held with greatest tenacity by those most accustomed to the mischance of falling into adversity, and is most acceptably expounded with disproof - an intellectual disorder, yielding to no treatment but death. It is hereditary, but fortunately not contagious.
Ambrose BierceLogic: The art of thinking and reasoning in strict accordance with the limitations and incapacities of the human misunderstanding.
Ambrose Bierce