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

It is in the gift for employing all the vicissitudes of life to one's own advantage and to that of one's craft that a large part of genius consists.

Prejudices are so to speak the mechanical instincts of men: through their prejudices they do without any effort many things they would find too difficult to think through to the point of resolving to do them.

The fly that doesn't want to be swatted is most secure when it lights on the fly-swatter.

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

I have never yet met anyone who did not think it was an agreeable sensation to cut tinfoil with scissors.

Men still have to be governed by deception.