Reading furnishes the mind only with materials of knowledge; it is thinking that makes what we read ours.

If you can't explain it simply, you don't understand it well enough.

If you're not learning while you're earning, you're cheating yourself out of the better portion of your compensation.

Imagination is the source of every form of human achievement. And it's the one thing that I believe we are systematically jeopardizing in the way we educate our children and ourselves.

If one cannot enjoy reading a book over and over again, there is no use in reading it at all.

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

The most savage controversies are those about matters as to which there is no good evidence either way.

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

It isn't what we don't know that gives us trouble, it's what we know that ain't so.

The real solution lies in a world in which charity will have become unnecessary.

Evil being the root of mystery, pain is the root of knowledge.

The schools ain't what they used to be and never was.

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

Just because I don't care doesn't mean I don't understand.

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.

No man's knowledge here can go beyond his experience.

As we acquire more knowledge, things do not become more comprehensible but more mysterious.

It is better to know how to learn than to know.

A witty saying proves nothing.

You can never be overdressed or overeducated.

I like poems you can tack all over with a hammer and there are no hollow places.