There are two primary choices in life: to accept conditions as they exist, or accept the responsibility for changing them.

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

Turn and face the strange.

You never change things by fighting the existing reality. To change something, build a new model that makes the existing model obsolete.

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.

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.

Those who cannot change their minds cannot change anything.

We should seek the greatest value of our action.