My business is to teach my aspirations to confirm themselves to fact, not to try and make facts harmonize with my aspirations.

In fact a favourite problem of Tyndall is-Given the molecular forces in a mutton chop, deduce Hamlet or Faust therefrom. He is confident that the Physics of the Future will solve this easily.

The rung of a ladder was never meant to rest upon.

History warns us that it is the customary fate of new truths to begin as heresies and to end as superstitions.

Irrationally held truths may be more harmful than reasoned errors.

Only one absolute certainty is possible to man, namely that at any given moment the feeling which he has exists.

The rules of the game are what we call the laws of nature.