The reading of all good books is like conversation with the finest men of past centuries.

Reading furnishes the mind only with materials of knowledge; it is thinking that makes what we read ours.

Dare to think for yourself.

In mathematics you don't understand things. You just get used to them.

Don't worry that children never listen to you; worry that they are always watching you.

The ability to observe without evaluating is the highest form of intelligence.

If I could explain it to the average person, I wouldn't have been worth the Nobel Prize.

There is no authority who decides what is a good idea.

Never help a child with a task at which he feels he can succeed.

Evil being the root of mystery, pain is the root of knowledge.

You can never be overdressed or overeducated.

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

Courage, conviction and confidence.

Real knowledge is to know the extent of one's ignorance.

Seek knowledge from the cradle to the grave.

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

The most savage controversies are those about matters as to which there is no good evidence either way.

No man's knowledge here can go beyond his experience.

Medicine is my lawful wife and literature my mistress; when I get tired of one, I spend the night with the other.

It isn't what we don't know that gives us trouble, it's what we know that ain't so.

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.