And in man is a three-pound brain which, as far as we know, is the most complex and orderly arrangement of matter in the universe.

All the hundreds of millions of people who, in their time, believed the Earth was flat never succeeded in unrounding it by an inch.

Until now in world's history, whenever we've had a dark age, its been temporary and local. And other parts of the world have been doing fine. And eventually, they help you get out of the dark age. We are now facing a possible dark age which is going to be world-wide and permanent! That's not fun. That's a different thing. But once we have established many worlds, we can do whatever we want as long as we do it one world at a time.

Science doesn't purvey absolute truth. Science is a mechanism... for testing your thoughts against the universe.

Inertia! Our ruling class knows one law; no change. Despotism! They know one rule; force. Maldistribution! They know one desire; to hold what is theirs.

It is the chief characteristic of the religion of science that it works.

Nothing interferes with my concentration. You could put on an orgy in my office and I wouldn't look up. Well, maybe once.