A theory is scientific only if it can be disproved. But the moment you try to cover absolutely everything the chances are that you cover nothing.

Religion divides us, while it is our human characteristics that bind us to each other.

[Science doesn't deal with facts; indeed] fact is an emotion-loaded word for which there is little place in scientific debate.

Time is that which is manufactured by clocks.

An observer situated in a nebula and moving with the nebula will observe the same properties of the universe as any other similarly situated observer at any time.

... an opportunity to allow the bees in one's bonnet to buzz even more noisily than usual.

[Newton's calculations] entered the marrow of what we know without knowing how we know it.

Our humanist attitude should therefore throughout be to stress what we all have in common with each other and relegate quarrelsome religion to the private domain where it can do [less] harm.

We find no sense in talking about something unless we specify how we measure it; a definition by the method of measuring a quantity is the one sure way of avoiding talking nonsense.

Men in general are as much affected by what a thing appears to be as by what it is, indeed they are frequently influenced more by appearances than by reality.

Let your words be petty and actions plenty!

A man who listens because he has nothing to say can hardly be a source of inspiration. The only listening that counts is that of the talker who alternately absorbs and expresses ideas.

I am proud that [I was] , , , enabled to guide this great talent . . . towards the superb fulfillment of its individual potentialities, towards the greatest independence.

We're all proud of making little mistakes. It gives us the feeling we don't make any big ones.

Don't underestimate me.

Thought is a kind of opium; it can intoxicate us, while still broad awake; it can make transparent the mountains and everything that exists.

In a way an umpire is like a woman. He makes quick decisions, never reverses them, and doesn't think you're safe when you're out.

The very remembrance of my former misfortune proves a new one to me.

People have always said - those words, 'too conservative,' is fairly relative. I'm sure that they probably said that about Thomas Jefferson and George Washington and Benjamin Franklin.