That men do not learn very much from the lessons of history is the most important of all the lessons that history has to teach.

Don't learn to do, but learn in doing.

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

An investment in knowledge pays the best interest.

I am a part of everything that I have read.

They say a little knowledge is a dangerous thing, but it's not one half so bad as a lot of ignorance.

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

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

Real learning comes about when the competitive spirit has ceased.

Language is courage: the ability to conceive a thought, to speak it, and by doing so to make it true.

The deepest sin against the human mind is to believe things without evidence.

Education is a system of imposed ignorance.

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

The idea is to try to give all the information to help others to judge the value of your contribution; not just the information that leads to judgment in one particular direction or another.

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

You can never be overdressed or overeducated.

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

Integrity without knowledge is weak and useless, and knowledge without integrity is dangerous and dreadful.

Common sense is the collection of prejudices acquired by age eighteen.

It is better to know how to learn than to know.

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