My personal beliefs seem to stem from what I've heard described as an 'oversoul'. I don't know what tradition that comes from originally, but it fits what I've experienced. I kind of see it as one's whole 'spirit'- every aspect and memory of every person or thing you've ever been and have yet to be, your basic nature, and the life lessons of all the incarnations you might make- being contained in one sort of 'medicine bag'. When you incarnate, or take on a form, one of those... I guess you could say 'spirits' in the bag is what goes out to be whatever that form is. When that incarnation is over, the spirit flies back to the Oversoul with everything that it has learned. My interpretation is that, when that Oversoul has fulfilled all of its work and has helped others enough, it is given the choice to have its energy merged with that of... well, I'm not sure what it is. Existence, Spirit, Diety, or what the best phrase for it would be.