As an unbeliever, I ask leave to plead that humanity has been real gainer from scepticism, and that the gradual and growing rejection of Christianity—like the rejection of the faiths which preceded it—has in fact added, and will add, to man's happiness and well being. I maintain that in physics science is the outcome of scepticism, and that general progress is impossible without scepticism on matters of religion. I mean by religion every form of belief which accepts or asserts the supernatural.