The christening of Europe seemed to all our ancestors, whether they welcomed it themselves as Christians, or, like Gibbon, deplored it as humanistic unbelievers, a unique, irreversible event. But we have seen the opposite process. Of course the un-christening of Europe in our time is not quite complete; neither was her christening in the Dark Ages. But roughly speaking we may say that whereas all history was for our ancestors divided into two periods, the pre-Christian and the Christian, and two only, for us it falls into three—the pre-Christian, the Christian, and what may reasonably be called the post-Christian. This surely must make a momentous difference