God: personified incomprehensibility.

If we make a couple of discoveries here and there we need not believe things will go on like this for ever. Just as we hit water when we dig in the earth, so we discover the incomprehensible sooner or later.

A donkey appears to me like a horse translated into Dutch.

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.

Astronomy is perhaps the science whose discoveries owe least to chance, in which human understanding appears in its whole magnitude, and through which man can best learn how small he is.

The natural scientists of the previous age knew less than we do and believed they were very close to the goal: we have taken very great steps in its direction and now discover we are still very far away from it. With the most rational philosophers an increase in their knowledge is always attended by an increased conviction of their ignorance.

Everyone should study at least enough philosophy and belles-lettres to make his sexual experience more delectable.