Physics is mathematical not because we know so much about the physical world, but because we know so little; it is only its mathematical properties that we can discover.

Citizens as conceived by governments are persons who admire the status quo and are prepared to exert themselves for its preservation. Oddly enough, while all governments aim at producing men of this type to the exclusion of all other types, their heroes in the past are of exactly the sort that they aim at preventing in the present. Americans admire George Washington and Jefferson, but imprison those who share their political opinions.

Religion is something left over from the infancy of our intelligence, it will fade away as we adopt reason and science as our guidelines.

What the world needs is not dogma but an attitude of scientific inquiry combined with a belief that the torture of millions is not desirable, whether inflicted by Stalin or by a Deity imagined in the likeness of the believer

When we have told how things behave when they are electrified, and under what circumstances they are electrified, we have told all there is to know

Love is a little haven of refuge from the world.

It will be said that the joy of mental adventure must be rare, that there are few who can appreciate it, and that ordinary education can take no account of so aristocratic a good. I do not believe this. The joy of mental adventure is far commoner in the young than in grown men and women. ...It is rare in later life because everything is done to kill it during education.