In theory, there is no difference between theory and practice. But in practice, there is. (Yogi Berra)

A friendship founded on business is better than a business founded on friendship. (John D. Rockefeller)

A mathematician is a device for turning coffee into theorems. (Paul Erdos)

But at my back I always hear Time’s winged chariot hurrying near. (Andrew Marvell)

All are lunatics, but he who can analyze his delusion is called a philosopher. (Ambrose Bierce)