Respectability, regularity, and routine - the whole cast-iron discipline of a modern industrial society - have atrophied the artistic impulse, and imprisoned love so that it can no longer be generous and free and creative, but must be either stuffy or furtive.

To create a healthy philosophy you should renounce metaphysics but be a good mathematician.

Religions that teach brotherly love have been used as an excuse for persecution, and our profoundest scientific insight is made into a means of mass destruction.

Change is one thing, progress is another.

There can't be a practical reason for believing something that is not true.

Cruel men believe in a cruel god and use their belief to excuse their cruelty. Only kindly men believe in a kindly god, and they would be kindly in any case.

The first essential character [of civilization], I should say, is forethought. This, indeed, is what mainly distinguishes men from brutes and adults from children.