“I am by nature an optimist and by intellectual conviction a pessimist.”
“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.”
“I will be the first to admit that I am a pessimist by nature. It is, after all, the wisest way to be. We pessimists have everything to gain, whereas optimists have a fifty-fifty chance of being disappointed.”
“I am neither an optimist nor pessimist, but a possibilist.”
“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.”