To sin is a human business, to justify sins is a devilish business.

To tell the truth is very difficult, and young people are rarely capable of it.

The truth is obtained like gold, not by letting it grow bigger, but by washing off from it everything that isn't gold

If patriotism is good, then Christianity, which gives peace, is an idle dream, and the sooner this teaching is eradicated, the better. But if Christianity really gives peace, and if we really want peace, then patriotism is a leftover from barbarous times, which must not only not be evoked and taught, as we now do, but which must be eradicated by all means of preaching, persuasion, contempt, and ridicule. If Christianity is the truth, and if we wish to live in peace, then we must not only have no sympathy for the power of our country, but must even rejoice in its weakening and contribute to it.

The most difficult subjects can be explained to the most slow- witted man if he has not formed any idea of them already; but the simplest thing cannot be made clear to the most intelligent man if he is firmly persuaded that he knows already, without a shadow of doubt, what is laid before him.

There is no significant idea which cannot be explained to an intelligent twelve year old boy in fifteen minutes.

Reason unites us, not only with our contemporaries, but with men who lived two thousand years before us, and with those who will live after us.