The whole problem with the world is that fools and fanatics are always so certain of themselves, and wiser people so full of doubts.

If an opinion contrary to your own makes you angry, that is a sign that you are subsciously aware of having no good reason for thinking as you do. [...] The most savage controversies are those about matters as to which there is no good evidence either way. Persecution is used in theology, not in arithmetic, because in arithmetic there is knowledge, but in theology there is only opinion. So whenever you find yourself getting angry about a difference of opinion, be on your guard; you will probably find, on examination, that your belief is going beyond what the evidence warrants.

Mankind has become so much one family that we cannot insure our own prosperity except by insuring that of everyone else.

Science, by itself cannot, supply us with an ethic.

The tragedy of the people of Palestine is that their country was “given” by a foreign power to another people for the creation of a new state. The result was that many hundreds of thousands of innocent people were made permanently homeless. With every new conflict their numbers increased. How much longer is the world willing to endure this spectacle of wanton cruelty?

There is no excuse for deceiving children. And when, as must happen in conventional families, they find that their parents have lied, they lose confidence in them and feel justified in lying to them.

The fundamental defect of fathers, in our competitive society, is that they want their children to be a credit to them.