I don't know if this has been brought up at some time in the past, so I figured I might mention it. It has seemed to me for a long time that Zeal, this idea of a great ancient land floating high above the earth, might be based upon the movie Castle in the Sky. For those who don't know, it's a Japanese movie by Miyazaki (probably the only anime I actually like.) For those who do know it: am I just throwing together ill-placed connections here? It strikes me as possible, though. It is not inconceivable that Kato knew of the movie when he wrote CT (if I'm not mistaken Miyazaki's movies are some of the most famous in Japan.) And remember even this: the people of this 'castle in the sky', the kingdom of Laputa, possessed, in the movie, a mineral-gem named Levistone (Etherium in the English dub), that allowed the castle-land to float. That stikes me as markedly similar to the way in which the sunstone was used to keep Zeal in the sky. Again, it might just be me, however. Any other thoughts?