If you meant to continue a discussion that was on another thread (can't find it now) about Spike's soul, and/or the concept of the soul in the shows, I would agree that Inside/Out is the right place. I hope you will post this thread, because I think it is a fascinating subject!
I think the Time Life Mysteries of the Unknown had a volume on "The Search for the Soul." It's canonically part of Giles's Library. That would be a great name for a sub forum, too bad everything is taken.