Although modesty is natural to man, it is not natural to children. Modesty only begins with the knowledge of evil.

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

The first idea the child must acquire is that of the difference between good and evil.

I learned very early the difference between knowing the name of something and knowing something.

Real learning comes about when the competitive spirit has ceased.

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

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

Don't worry that children never listen to you; worry that they are always watching you.

Dare to think for yourself.

The man who does not read good books has no advantage over the man who can't read them.

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

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

Liberty without Learning is always in peril and Learning without Liberty is always in vain.

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

The progressive development of man is vitally dependent on invention.

Reading without reflecting is like eating without digesting.

The secret of life is not enjoyment but education through experience.

Science is not only a disciple of reason but, also, one of romance and passion.

The great difficulty in education is to get experience out of ideas.

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

A spirit of national masochism prevails, encouraged by an effete corps of impudent snobs who characterize themselves as intellectuals.