"There are three phrases that make possible the world of writing about the world of not-yet (you can call it science fiction or speculative fiction; you can call it anything you wish) and they are simple phrases: What if . . . ? If only . . . If this goes on . . . "What if . . . ?" gives us change, a departure from our lives. (What if aliens landed tomorrow and gave us everything we wanted, but at a price?) "If only . . ." lets us explore the glories and dangers of tomorrow. (If only dogs could talk. If only I were invisible.) "If this goes on . . ." is the most predictive of the three, although it doesn't try to predict an actual future with all its messy confusion. Instead, "If this goes on . . ." fiction takes an element of life today, something clear and obvious and normally something troubling, and asks what would happen if that thing, that one thing, became bigger, became all-pervasive, changed the way we thought and behaved. (If this goes on, all communication everywhere will be through text messages or computers, and direct speech between two people, without a machine, will be outlawed.)"