It is of no use to possess a lively wit if it is not of the right proportion: the perfection of a clock is not to go fast, but to be accurate.

The favorites of fortune or of fame topple from their pedestals before our eyes without diverting us from ambition.

Clearness ornaments profound thoughts.

Great men, like nature, use simple language.

A new principle is an inexhaustible source of new views.

We ought never to be afraid to repeat an ancient truth, when we feel that we can make it more striking by a neater turn, or bring it alongside of another truth, which may make it clearer, and thereby accumulate evidence. It belongs to the inventive faculty to see clearly the relative state of things, and to be able to place them in connection; but the discoveries of ages gone by belong less to their first authors than to those who make them practically useful to the world.

As soon as an opinion becomes common it is sufficient reason for men to abandon it and to uphold the opposite opinion until that in its turn grows old, and they require to distinguish themselves by other things. Thus if they attain their goal in some art or science, we must expect them soon to cast it aside to acquire some fresh fame, and this is partly the reason why the most splendid ages degenerate so quickly, and, scarcely emerged from barbarism, plunge into it again.