"It has always been my rule never to smoke when asleep, and never to refrain when awake."

"I thoroughly disapprove of duels. If a man should challenge me, I would take him kindly and forgivingly by the hand and lead him to a quiet place and kill him."

"If you pick up a starving dog and make him prosperous, he will not bite you; that is the principal difference between a dog and a man."

"The history of our race, and each individual's experience, are sown thick with evidence that a truth is not hard to kill and that a lie told well is immortal."

"We owe a deep debt of gratitude to Adam, the first great benefactor of the human race: he brought death into the world."

"A lie can travel halfway round the world while the truth is putting on its shoes."

"The man who has received a benefit ought always to remember it, but he who has granted it ought to forget the fact at once."

"The work goes on, the cause endures, the hope still lives and the dreams shall never die."

"A bird that you set free may be caught again, but a word that escapes your lips will not return."

"One problem with gazing too frequently into the past is that we may turn around to find the future has run out on us."

"When I'm working on a problem, I never think about beauty. I think only how to solve the problem. But when I have finished, if the solution is not beautiful, I know it is wrong."

"You must be willing to protect yourself and what you cherish, no matter what the cost."