“Sometimes a pessimist is only an optimist with extra information.”
“The world belongs to optimists. Pessimists are only spectators.”
“The difference between an optimist and a pessimist? An optimist laughs to forget but a pessimist forgets to laugh.”
“Both optimists and pessimists contribute to society. The optimist invents the aeroplane, the pessimist the parachute.”
“The the question whether I am a pessimist or an optimist, I answer that my knowledge is pessimistic, but my willing and hope are optimistic.”
“Don't ever become a pessimist, Ira; a pessimist is correct oftener than an optimist, but an optimist has more fun--and neither can stop the march of events.”