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

If the facts don't fit the theory, change the facts.

Most people have never learned that one of the main aims in life is to enjoy 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 deepest sin against the human mind is to believe things without evidence.

To read is to fly: it is to soar to a point of vantage which gives a view over wide terrains of history, human variety, ideas, shared experience and the fruits of many inquiries.

Better know nothing than half-know many things.

My weapon is literature

I decided to teach because I think that any person who studies philosophy has to be involved actively.

A spirit of national masochism prevails, encouraged by an effete corps of impudent snobs who characterize themselves as intellectuals.

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

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.

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

The progressive development of man is vitally dependent on invention.

The secret of life is not enjoyment but education through experience.

Dare to think for yourself.

The delight of opening a new pursuit, or a new course of reading, imparts the vivacity and novelty of youth even to old age.

If you want the present to be different from the past, study the past.

The most important part of teaching is to teach what it is to know.

To every action there is always an equal and opposite or contrary, reaction

All knowledge that the world has ever received comes from the mind; the infinite library of the universe is in our own mind.