The only true wisdom is in knowing you know nothing.

Ignorance, the root and stem of all evil.

The more I see, the less I know for sure.

Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.

People who boast about their I.Q. are losers.

The most important knowledge is that which guides the way you lead your life.

If you can't explain it to a six year old, you don't understand it yourself.

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

We should seek the greatest value of our action.