I've never seen a monument erected to a pessimist.Paul Harvey
The optimist thinks that this is the best of all possible worlds. The pessimist knows it.OptimismRobert Oppenheimer
Society needs both optimists and pessimists. For example, an optimist invented the airplane while a pessimist invented the parachute.OptimismUnknown
The pessimist complains about the wind;
The optimist expects it to change;
The realist adjusts the sails.