If you can't explain it simply, you don't understand it well enough.

The first idea the child must acquire is that of the difference between good and evil.

What is freedom of expression? Without the freedom to offend, it ceases to exist.

Civilization is a race between disaster and education.

There is one quality which one must possess to win, and that is definiteness of purpose, the knowledge of what one wants, and a burning desire to possess it.

Science is a way of thinking much more than it is a body of knowledge.

Opinion is the medium between knowledge and ignorance.

Reading is to the mind what exercise is to the body.

Science is what we have learned about how to keep from fooling ourselves.

Reading without reflecting is like eating without digesting.

For a successful technology, reality must take precedence over public relations, for Nature cannot be fooled.

Industrialize or perish.

Patience is a virtue, and I'm learning patience. It's a tough lesson.

There is nothing more notable in Socrates than that he found time, when he was an old man, to learn music and dancing, and thought it time well spent.

Courage, conviction and confidence.

Physics is like sex: sure, it may give some practical results, but that's not why we do it.

It took us three years to build the NeXT computer. If we'd given customers what they said they wanted, we'd have built a computer they'd have been happy with a year after we spoke to them - not something they'd want now.

The highest activity a human being can attain is learning for understanding, because to understand is to be free.

Words can be like X-rays if you use them properly - they'll go through anything. You read and you?re pierced.

It is what you read when you don't have to that determines what you will be when you can't help it.

Books! I dunno if I ever told you this, but books are the greatest gift one person can give another.