No power and no treasure can outweigh the extension of our knowledge.

It is beyond a doubt that all our knowledge begins with experience.

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

When you know better you do better.

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.

Imagination is the source of every form of human achievement. And it's the one thing that I believe we are systematically jeopardizing in the way we educate our children and ourselves.

I cannot live without books.

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

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

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

Education is a system of imposed ignorance.

A cynic is a man who knows the price of everything, and the value of nothing.

Many much-learned men have no intelligence.

All stable processes we shall predict. All unstable processes we shall control.

Education is the best friend. An educated person is respected everywhere. Education beats the beauty and the youth.

Learning never exhausts the mind.

A man who has never gone to school may steal a freight car; but if he has a university education, he may steal the whole railroad.

I am indebted to my father for living, but to my teacher for living well.

A thought is an idea in transit.

Intelligence plus character-that is the goal of true education.

I have no special talents. I am only passionately curious.