Well, exactly, they work on different levels - Superman is macro and Batman is micro. Superman is space opera and Flash Gordon and Kaiju, Batman is '30's gangster films and 'On the Waterfront' and 'Dr. Jekyll and Mr. Hyde'. (It would, in fact, be interesting to compile a film library of the two characters - as I noted a while back on the old board, Batman is an extraordinarily cinematic character, both in terms of the amount of films/shows/cartoons he's showed up in, and in the amount of films that are acknowledged influences on him. Come to think of it, though, Superman is probably one of the only characters who can compete with him in that regard - he doesn't have as much in the way of cinematic influences, but they ARE there - Flash Gordon serials, for instance - and he's had almost as many appearances onscreen as Batman. It'd make for an interesting compilation.) As for the two poles - that IS an interesting way of looking at it, but it all boils down, in my opinion, to just why they STARTED to wear the costume and fight the fight. Batman's 'make people not die' motivation springs from childhood tragedy, but if you see Superman's 'help people live' motivation as a result of his interplanetary origins, then it can't really be seen as the reason he started the neverending battle, since he donned the costume BEFORE that. If you ignore for the purpose of argument the whole Superboy thing, which mucks about with a lot of his early history, Clark Kent first became Superman in both chronologies at the urging of his parents - Pre-Crisis, it was because of Jonathan Kent's dying wish, Post-Crisis it was at his suggestion after Clark had had problems with the lack of a secret identity. Krypton added a whole new element of tragedy to his story, of course, once he'd found out about it, but his first and primary motivations for fighting crime, in both continuities, were simply because he was raised with strong moral values and wanted to do his parents proud.