The secret of change is to focus all of your energy, not on fighting the old, but on building the new.

Be the change that you wish to see in the world.

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

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

Intelligence without ambition is a bird without wings.

Everyone thinks of changing the world, but no one thinks of changing himself.

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.