Black holes are where God divided by zero.

Shoot for the moon. Even if you miss it you will land among the stars.

Science is the record of dead religions.

Metaphysics is a dark ocean without shores or lighthouse, strewn with many a philosophic wreck.

Philosophy consists very largely of one philosopher arguing that all others are jackasses. He usually proves it, and I should add that he also usually proves that he is one himself.

Most institutions demand unqualified faith; but the institution of science makes skepticism a virtue.

There are in fact two things, science and opinion; the former begets knowledge, the latter ignorance.

The beginning of wisdom is found in doubting; by doubting we come to the question, and by seeking we may come upon the truth.

This only is certain, that there is nothing certain; and nothing more miserable and yet more arrogant than man.

Happy is he who gets to know the reasons for things.