“The optimist sees the doughnut, the pessimist sees the hole.”

“...an optimistic mind-set finds dozens of possible solutions for every problem that the pessimist regards as incurable.”

“The optimist sees opportunity in every danger; the pessimist sees danger in every opportunity.”

“The optimist sees the rose and not its thorns; the pessimist stares at the thorns, oblivious to the rose.”

“Leadership is the ability to see what no one else sees, to listen when others talk and the ability to be optimistic when others are pessimistic.”

“Man is brilliant at solving problems; but solving them only makes him the victim of his own childishness and laziness. It is this recognition that has made almost every major philosopher in history a pessimist.”

“Just because you can't see something doesn't mean it's not there.”