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

It is not enough for the teacher to love the child. She must first love and understand the universe. She must prepare herself, and truly work at it.

There is one quality which one must possess to win, and that is definiteness of purpose, the knowledge of what one wants, and a burning desire to possess it.

It is possible to fly without motors, but not without knowledge and skill.

The man who is fond of books is usually a man of lofty thought, and elevated opinions.

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

We could never learn to be brave and patient, if there were only joy in the world

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

My alma mater was books, a good library.... I could spend the rest of my life reading, just satisfying my curiosity.

Educate the children and it won't be necessary to punish the men.

He who would learn to fly one day must first learn to stand and walk and run and climb and dance; one cannot fly into flying.

Know what you are talking about.

The whole of science is nothing more than a refinement of everyday thinking.

Science is a rising force, It is creating a new world about us. It needs to be watched and pressed into service, and in any case, it would be courting disaster to ignore it.

Human behavior flows from three main sources: desire, emotion, and knowledge

Books are as useful to a stupid person as a mirror is useful to a blind person.

All knowledge that the world has ever received comes from the mind; the infinite library of the universe is in our own mind.

A little knowledge that acts is worth infinitely more than much knowledge that is idle.

Reading without reflecting is like eating without digesting.

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

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