Chance ... must be something more than the name we give to our ignorance.

Most striking at first is the appearance of sudden illumination, a manifest sign of long unconscious prior work.

We also know how cruel the truth often is, and we wonder whether delusion is not more consoling.

Doubting everything and believing everything are two equally convenient solutions that guard us from having to think

One geometry cannot be more true than another; it can only be more convenient.

It may happen that small differences in the initial conditions produce very great ones in the final phenomena. A small error in the former will produce an enormous error in the later. Prediction becomes impossible, and we have the fortuitous phenomena.

In the old days when people invented a new function they had something useful in mind.