"The world is a dangerous place to live; not because of the people who are evil, but because of the people who don't do anything about it."

"I never think of the future – it comes soon enough."

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."

"If you want to live a happy life, tie it to a goal, not to people or things."

"The only way to escape the corrupting influence of praise is to go on working."