Knowledge isn't free. You have to pay attention.

Science is the organized skepticism in the reliability of expert opinion.

Everything is interesting if you go into it deeply enough.

The great difficulty is in trying to imagine something that you have never seen, that is consistent in every detail with what has already been seen, and that is different from what has been thought of; furthermore, it must be definite and not a vague proposition.

The highest forms of understanding we can achieve are laughter and human compassion.

The first principle is that you must not fool yourself and you are the easiest person to fool.

Study hard what interests you the most in the most undisciplined, irreverent and original manner possible.

The principal goal of education is to create individuals who are capable of doing new things.

The best way to treat children is to treat them as equals.

Intelligence is what you use when you don't know what to do.