We cannot remember too often that when we observe nature, and especially the ordering of nature, it is always ourselves alone we are observing.

The most heated defenders of a science, who cannot endure the slightest sneer at it, are commonly those who have not made very much progress in it and are secretly aware of this defect.

A schoolteacher or professor cannot educate individuals, he educates only species.

We can see nothing whatever of the soul unless it is visible in the expression of the countenance; one might call the faces at a large assembly of people a history of the human soul written in a kind of Chinese ideograms.

Actual aristocracy cannot be abolished by any law: all the law can do is decree how it is to be imparted and who is to acquire it.

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.

God creates the animals, man creates himself.