Knowing others is wisdom, knowing yourself is Enlightenment.

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

Industrialize or perish.

If you're teaching today what you were teaching five years ago, either the field is dead or you are.

Education is the ability to listen to almost anything without losing your temper or your self-confidence.

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

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

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

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.

Free the child's potential, and you will transform him into the world.

Reading without reflecting is like eating without digesting.

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

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.

I think that kids have a greater capacity for processing things than we give them credit for.

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

In mathematics you don't understand things. You just get used to them.

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

Civilization is a race between disaster and education.

I am so clever that sometimes I don't understand a single word of what I am saying.

Investigate, educate and organize.