I've been thinking about this recently because I'm planning to write a short story relating to the subject. Any help would be great.
good for you. I think it's the sum of a person's deeds, if free will exists, and fate, if not. Take your pick. (That bit I borrowed from the western mystics) Assuming you're an individualist, you have some will, and you can choose your path, and the soul is a path-dependent function. Just like in calculus. Depending on how you differentiate, you get a different result. So it's not like entropy (what the hindu call Shiva), or enthalpy (what the Judeochristoislamists call "the devil"), or Internal Energy (what the Eastern Mystics call Karma). It's more like work or heat, in that sense, since the path you take very much defines the soul. I has no particles with non-zero rest mass, and therefore doesn't need to abide by the laws of contemporary physics. It's an ethereal entity. (that bit I borrowed from the Jews) It lives without form or particle, and enters and exits bodies upon the birth and death, respectively, of that body. It is forever. Really forever. Not like diamonds (that's just an advertising gimmick.) Creatures with souls are not allowed by the gods to give souls to their creations. That's an important point. So it's not something that androids, like Lieutennant commander Data, can have. It's something animals (even extraterrestrials, like Roger on American Dad) can have. Maybe also plants have them. And lower life forms too maybe. But artificial life forms do not have them. I also think that the gods themselves have no souls, but are somewhat envious of those who do. (That bit I borrowed from the buddhists).
And that's the sum of my pantheistic understanding of souls: They are forever. Gods are not allowed to have them. They do not have form. They determine your ethereal trajectory.
I'll check to see what Elvis had to say about them.