Why are these possible worlds and alternate realities I've been aggregating necessary, at least to the England that dreamed them?
In part -- as came through in the comments to yesterday's post -- these Other Worlds offer a potentially affirmative vision, a version of the world that doesn't necessarily include the circumscriptions, foreclosures, and abjections through which stable identities come into being. True, many times these worlds open a portal upon memories of historical traumas that limn the present. Just as frequently, through such a portal can be glimpsed a more capacious ordering of that present -- and by more capacious I also mean more enchanted and more just.
One way of explaining the allure of these Other Worlds is to emphasize their escapist potential, since they are in part oneiric geographies that, once entered, could allow the dreamer to depart a troubled present without changing it, at least for a while. But that's only part of the story. By asking what the present would be like if it were configured differently, by wondering what Now would be if Then were remembered either better or simply differently, these Other Worlds offer, at least potentially, the opportunity for trenchant social critique, for imaging the world otherwise.
Fantasy is likely never the best way to change the mundane givenness of a particular life, of a particular world ... but fantasies of alternate realities do emphasize the contingency, the non-inevitability, of the world as currently known. Medieval England's Other Worlds invited the nation to ponder what it had abandoned to become itself, what other possibilities there might be for forming community in the realm.