The most perfect ape cannot draw an ape; only man can do that; but, likewise, only man regards the ability to do this as a sign of superiority.

Above all things expand the frontiers of science: without this the rest counts for nothing.

A book which, above all others in the world, should be forbidden, is a catalogue of forbidden books.

Once we know our weaknesses they cease to do us any harm.

People who never have any time on their hands are those who do the least.

What is called an acute knowledge of human nature is mostly nothing but the observer's own weaknesses reflected back from others.

To write brashly about some things, it is almost necessary not to know much about them.