Properly speaking, such work is never finished; one must declare it so when, according to time and circumstances, one has done one's best.

Nothing is more consonant with Nature than that she puts into operation in the smallest detail that which she intends as a whole.

God could cause us considerable embarrassment by revealing all the secrets of nature to us: we should not know what to do for sheer apathy and boredom.

The public wishes itself to be managed like a woman; one must say nothing to it except what it likes to hear.

There is no permanence in doubt; it incites the mind to closer inquiry and experiment, from which, if rightly managed, certainty proceeds, and in this alone can man find thorough satisfaction.

All the knowledge I possess everyone else can acquire, but my heart is all my own.

Everyone is deceived in his hopes, cheated in his expectations.