  Critically, for Lewis, worlds and their denizens do not differ in the manner in which they exist. The actual world does not enjoy a kind of privileged existence that sets it apart from other worlds. Rather, what makes the actual world actual is simply that it is our world, the world that we happen to inhabit. Other worlds and their inhabitants exist just as robustly as we do, and in precisely the same sense; all worlds and all of their denizens are equally real.[17] A significant semantic corollary of this thesis for Lewis is that the word ‘actual’ in the phrase ‘the actual world’ does not indicate any special property of the actual world that distinguishes it from all other worlds; likewise, an assertion of the form ‘a is actual’ does not indicate any special property of the individual a that distinguishes it from the objects existing in other worlds. Rather, ‘actual’ is simply an indexical whose extension is determined by the context of utterance. Thus, the referent of ‘the actual world’ in a given utterance is simply the world of the speaker, just as the referent of an utterance of ‘the present moment’ is the moment of the utterance; likewise, an utterance of the form ‘a is actual’ indicates only that a shares the same world as the speaker. The speaker thereby ascribes no special property to a but, essentially, expresses no more than when she utters ‘a is here’, understood in the broadest possible sense. By the same token, when we speak of non-actual possibilia — Lewis's preferred label for the denizens of possible worlds — we simply pick out those objects that are not here in the broadest sense. In the mouth of an other-worldly metaphysician, we here are all among the non-actual possibilia of which she speaks in her lectures on de re modality. 