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.

Ignorance, the root and stem of all evil.

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

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.

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

Where there is shouting, there is no true knowledge.

Death may be the greatest of all human blessings.