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

The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge.

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.

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

An honest man is always a child.

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