But it is rather common to come up with something quite outlandish if you can find another way to reconcile certain extremely vile human behaviour.

If you run across a Son of Sam type character—a serial killer named David Berkowitz who murdered six people in New York City during the 1970s—or even a Hitler—and we all know what he did—it is much easier to write them off as some inhuman entity than just a whacked-out human being.

Otherwise, we would have to admit we are all capable of such atrocities. Hitler and the Son of Sam were both possessed by evil spirits, or the Devil himself. How could they have done what they did if not?