The only true wisdom is in knowing you know nothing.

Everything you can imagine is real.

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

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.

Insanity is doing the same thing over and over again and expecting different results.

The most important knowledge is that which guides the way you lead your life.

If you can't explain it to a six year old, you don't understand it yourself.

Only a life lived for others is a life worthwhile.

Why does the eye see a thing more clearly in dreams than the imagination when awake?