What is a Soul?

Recently I've been blogging about a trip I took to Denmark and Norway. Today I'll still be using some pictures from that trip, but today's subject is going to be something different. I've been thinking about science-fictional ways to provide for an afterlife in my novel-in-progress, Jim and the Flims. I thought about it quite a bit, and it was useful to read the "Eschatology" entry in the second edition of Clute and Nicholls, The Encyclopedia of Science Fiction .

My question today is simple.