Man is a complex being who makes deserts bloom and lakes die

Both optimists and pessimists contribute to our society. The optimist invents the airplane and the pessimist the parachute.

I still think sincere pessimism the unpardonable sin.

Optimism is denial for chumps with no life experience".
"What's pessimism?" I said.
"Religion without God.

So desperate was Kugel for things to turn out for the best, proclaimed Professor Jove, that he couldn't stop worrying about the worst. Hope, said Professor Jove, was Solomon Kugel's greatest failing.

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.