A habit of basing convictions upon evidence, and of giving to them only that degree or certainty which the evidence warrants, would, if it became general, cure most of the ills from which the world suffers.

In the part of this universe that we know there is great injustice, and often the good suffer, and often the wicked prosper, and one hardly knows which of those is the more annoying.

Do not feel certain of anything.

Punctuality is a quality the need of which is bound up with social co-operation. It has nothing to do with the relation of the soul to God, or with mystic insight, or with any of the matters with which the more elevated and spiritual moralists are concerned.

A marriage is likely to be called happy if neither party ever expected to get much happiness out of it.

War...seems a mere madness, a collective insanity.

It is undesirable to believe a proposition when there is no ground whatever for supposing it true