Mad, adj. Affected with a high degree of intellectual independence.

- Ambrose Bierce

Small minds are concerned with the extraordinary, great minds with the ordinary.

- Blaise Pascal

The surest sign that intelligent life exists elsewhere in the universe is that it has never tried to contact us.

- Bill Watterson

The intellect of the wise is like glass; it admits the light of heaven and reflects it.

- Augustus Hare

Don't leave home without your sword - your intellect.

- Alan Moore

Talent hits a target no one else can hit; Genius hits a target no one else can see.

- Arthur Schopenhauer

My mind rebels at stagnation. Give me problems, give me work, give me the most abstruse cryptogram, or the most intricate analysis, and I am in my own proper atmosphere. But I abhor the dull routine of existence. I crave for mental exaltation.

- Arthur Conan Doyle

To be able to fill leisure intelligently is the last product of civilization.

- Arnold J. Toynbee

There is no great genius without some touch of madness.

- Aristotle

Wit is educated insolence.

- Aristotle

Promise me you'll always remember: You're braver than you believe, and stronger than you seem, and smarter than you think.

- A. A. Milne

Genius creates, and taste preserves. Taste is the good sense of genius; without taste, genius is only sublime folly.

- Alexander Pope

The bookful blockhead, ignorantly read, With loads of learned lumber in his head.

- Alexander Pope

The difference between stupidity and genius is that genius has its limits.

- Albert Einstein

He who joyfully marches to music in rank and file has already earned my contempt. He has been given a large brain by mistake, since for him the spinal cord would suffice.

- Albert Einstein

Joy in looking and comprehending is nature's most beautiful gift.

- Albert Einstein

We should take care not to make the intellect our god; it has, of course, powerful muscles, but no personality.

- Albert Einstein

An intellectual is someone whose mind watches itself.

- Albert Camus

Be as smart as you can, but remember that it is always better to be wise than to be smart.

- Alan Alda

These little grey cells. It is up to them.

- Agatha Christie