Think good, and good follows. Think evil, and evil follows. You are what you think all day long.

The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.

Turn and face the strange.

People won't have time for you if you are always angry or complaining.

Intelligence without ambition is a bird without wings.

My goal is simple. It is a complete understanding of the universe, why it is as it is and why it exists at all.

Education is the most powerful weapon which you can use to change the world.

No matter what people tell you, words and ideas can change the world.

We should seek the greatest value of our action.