A question that sometimes drives me hazy: am I or are the others crazy?

The important thing is not to stop questioning. Curiosity has its own reason for existing.

It is the supreme art of the teacher to awaken joy in creative expression and knowledge.

He who can no longer pause to wonder and stand rapt in awe, is as good as dead; his eyes are closed.

The hardest thing to understand in the world is the income tax.

If people are good only because they fear punishment, and hope for reward, then we are a sorry lot indeed.

Once we accept our limits, we go beyond them.

Before God we are all equally wise – and equally foolish.

The monotony and solitude of a quiet life stimulates the creative mind.

Intellectual growth should commence at birth and cease only at death.

Only one who devotes himself to a cause with his whole strength and soul can be a true master. For this reason mastery demands all of a person.

The world is a dangerous place to live; not because of the people who are evil, but because of the people who don’t do anything about it.

You cannot simultaneously prevent and prepare for war.

Anyone who has never made a mistake has never tried anything new.

No problem can be solved from the same level of consciousness that created it.

Imagination is everything. It is the preview of life’s coming attractions.

Reality is merely an illusion, albeit a very persistent one.

If we knew what it was we were doing, it would not be called research, would it?

I live in that solitude which is painful in youth, but delicious in the years of maturity.

Nationalism is an infantile disease. It is the measles of mankind.