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

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

I am not an Athenian or a Greek, but a citizen of the world.

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

Where there is shouting, there is no true knowledge.

My brain is only a receiver, in the Universe there is a core from which we obtain knowledge, strength and inspiration. I have not penetrated into the secrets of this core, but I know that it exists.

Death may be the greatest of all human blessings.

I cannot teach anybody anything. I can only make them think.

Strong minds discuss ideas, average minds discuss events, weak minds discuss people