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

One test of the correctness of educational procedure is the happiness of the child.

Knowing others is wisdom, knowing yourself is Enlightenment.

Real knowledge is to know the extent of one's ignorance.

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

The fullness of knowledge only comes through the awareness of ignorance.

Courage, conviction and confidence.

Seek knowledge from the cradle to the grave.

It took us three years to build the NeXT computer. If we'd given customers what they said they wanted, we'd have built a computer they'd have been happy with a year after we spoke to them - not something they'd want now.

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

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

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

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

Knowledge becomes evil if the aim be not virtuous.

The idea is to try to give all the information to help others to judge the value of your contribution; not just the information that leads to judgment in one particular direction or another.

Education is an ornament for the prosperous, a refuge for the unfortunate.

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

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

The delight of opening a new pursuit, or a new course of reading, imparts the vivacity and novelty of youth even to old age.

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

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