"This only is certain, that there is nothing certain; and nothing more miserable and yet more arrogant than man."

"No mortal man, moreover is wise at all moments."

"In comparing various authors with one another, I have discovered that some of the gravest and latest writers have transcribed, word for word, from former works, without making acknowledgment."

"Why is it that we entertain the belief that for every purpose odd numbers are the most effectual?"

"The best plan is to profit by the folly of others."

"The only certainty is that nothing is certain."

"If you do not think about the future, you cannot have one."

"When honor and truth are at odds, let truth prevail."

"If you feel like you're under control you're just not going fast enough."

"Is sloppiness in speech caused by ignorance or apathy? I don't know and I don't care."

"Courage is grace under pressure."

"You find the meaning in life by giving yourself away not by satisfying yourself. The most gratifying thing, at 73 years old, is to be able to think that your life was used to help others."