Most of us also believe that things, as a whole, needn't have been just as they are. Rather, things might have been different in countless ways, both trivial and profound. History, from the very beginning, could have unfolded quite other than it did in fact: the matter constituting a distant star might never have organized well enough to give light; species that survived might just as well have died off; battles won might have been lost; children born might never have been conceived and children never conceived might otherwise have been born. In any case, no matter how things had gone they would still have been part of a single, maximally inclusive, all-encompassing situation, a single world. Intuitively, then, the actual world of which your immediate situation is a part is only one among many possible worlds.
Most of us also believe that things, as a whole, needn't have been just as they are. Rather, things might have been different in countless ways, both trivial and profound. History, from the very beginning, could have unfolded quite other than it did in fact: the matter constituting a distant star might never have organized well enough to give light; species that survived might just as well have died off; battles won might have been lost; children born might never have been conceived and children never conceived might otherwise have been born. In any case, no matter how things had gone they would still have been part of a single, maximally inclusive, all-encompassing situation, a single world. Intuitively, then, the actual world of which your immediate situation is a part is only one among many possible worlds.