The desire to understand the world and the desire to reform it are the two great engines of progress, without which human society would stand still or retrogress.

Science is what you know, philosophy is what you don't know.

The man who pursues happiness wisely will aim at the possession of a number of subsidiary interests in addition to those central ones upon which his life is built.

One should as a rule respect public opinion in so far as is necessary to avoid starvation and to keep out of prison, but anything that goes beyond this is voluntary submission to an unnecessary tyranny.

So far as I can remember, there is not one word in the Gospels in praise of intelligence.

When all experts agree, you need to watch out.

Next to worry probably one of the most potent causes of unhappiness is envy.