OOC: kali has hit the nail squarely on the head - "it is all speculative". Really, most of the theories in this thread are valid to a lesser or greater extent. There's nothing in the game to either fully confirm or unequivocally deny most of them... in the end, it's basically a matter of personal opinion. If one thing's certain, that is that it'd be nice to know... but unless Square or Hironobu Sakaguchi et al make some kind of official statement, we may never know. But then, that's where the fun is - trying to fill in the gaps. So many games these days are cut-and-dried, explained in one syllable words so that even the most obtuse gamer can understand them. It's great that FFVII still has us speculating, six years after its release...