None of this is meant to pour cold water on seasonal traditions, ritual celebrations or doing stuff together in general, all of which I think are very important - they certainly beat sitting at home watching TV. And the idea of Halloween being a time when strange stuff happens and otherworldly influences seep into ours has got centuries of folk belief behind it.

You've got to dig an awfully long way down before you find anything non-Christian, though - and those veils seem to be much more recent than you'd think.