Know what you are talking about.

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

Industrialize or perish.

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

Science is a way of thinking much more than it is a body of knowledge.

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

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

The white man is very clever. He came quietly and peaceably with his religion. We were amused at his foolishness and allowed him to stay. Now he has won our brothers, and our clan can no longer act like one. He has put a knife on the things that held us together and we have fallen apart.

Knowing others is wisdom, knowing yourself is Enlightenment.

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

When you know better you do better.

Those who fail to learn the lessons of history are doomed to repeat them.

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

Knowledge is of two kinds. We know a subject ourselves, or we know where we can find information upon it.

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

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

A little knowledge is a dangerous thing. So is a lot.

Just when I thought there wasn't room enough for another thought in my head, I had this great idea.

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

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.

Make it a rule never to give a child a book you would not read yourself.