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.