Ask yourself always: how can this be done better?

There exists a species of transcendental ventriloquism by means of which men can be made to believe that something said on earth comes from Heaven.

All mathematical laws which we find in Nature are always suspect to me, in spite of their beauty. They give me no pleasure. They are merely auxiliaries. At close range it is all not true.

The more experiences and experiments accumulate in the exploration of nature, the more precarious the theories become. But it is not always good to discard them immediately on this account. For every hypothesis which once was sound was useful for thinking of previous phenomena in the proper interrelations and for keeping them in context. We ought to set down contradictory experiences separately, until enough have accumulated to make building a new structure worthwhile.

In the world we live in, one fool makes many fools, but one sage only a few sages.

One might call habit a moral friction: something that prevents the mind from gliding over things but connects it with them and makes it hard for it to free itself from them.

We have no words for speaking of wisdom to the stupid. He who understands the wise is wise already.