“The man who is a pessimist before 48 knows too much; if he is an optimist after it he knows too little.”
“A man may be a pessimistic determinist before lunch and an optimistic believer in the will's freedom after it.”
“A pessimist is a person who has had to listen to too many optimists.”
“Only the man that knows to little, knows too much." Nero Wolfe”
“I am an optimist, unrepentant and militant. After all, in order not to be a fool, an optimist must know what a sad place the world can be. It is only the pessimist who finds this out anew every day.”
“A man who knows how little he knows is well, a man who knows how much he knows is sick. If, when you see the symptoms, you can tell, Your cure is quick.A sound man knows that sickness makes him sick and before he catches it his cure is quick.”