(Photograph) - The devil we may not know: Robocop is not an image usually associated with Old Nick, but some detect in his high-tech protruberances vestiges of the talons and torments of medieval demons. Others argue that we have erased the devil and that his absence signifies a modern reluctance to define what is ethical. In effect, less Satan means more evil. Marina Warner reviews Luther Link's The Devil: a mask without a face, page 18.