The world has little belief nowadays in the existence of a personal devil. If you meet Satan only, let us say, against the background of the Parisian society of Baudelaire's day you may be tempted to dismiss him as just part of the paraphernalia of a fashionable dilettantism; if you know him only in terms of medieval gargoyles and illuminations you may think him just one of the many childish fancies of a superstitious age. But in fact it is very unsound and unscientific to leave the matter there. Underneath all the superstitions of the Middle Ages, the fashionable posings of a later society, the unreasoning panic of the recurrent periods of witch-baiting, there does lie a world of a very different sort: a world of deadly and horrible seriousness where men know exactly what they are doing and do it and effectively, a world that you know to be real because of its horror. That world is with us still.