At old style sabbats, they say, the Devil would stand at the edge of the circle and whip up the dancing.
Literally.
(In the mountains back East, where I come from, they say that he'd use rose canes to do this. Yikes.)
One of the few truly effective ritual initiations that I've ever witnessed was priested by one of the local dungeon daddies. Now that scourging really meant something.
Burtrand of Minnesota Church of the Wicca—the grandfather of the local pagan community—used to insist that the scourge is one of the Horned's most important, and least understood, attributes.
