The only true wisdom is in knowing you know nothing.

Ignorance, the root and stem of all evil.

Intelligence is the ability to adapt to change.

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

Where there is shouting, there is no true knowledge.

I have noticed even people who claim everything is predestined, and that we can do nothing to change it, look before they cross the road.

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.