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

The only true wisdom is in knowing you know nothing.

Be as you wish to seem.

Ignorance, the root and stem of all evil.

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

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

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