Fred over at Occasional Fish has some worthy follow-up to the death of sci-fi post from last week, including a money quote from Ursula K. Le Guin:

But I think Harter could have done well to read Ursula K. Le Guin's introduction to The Left Hand of Darkness:

Science fiction is often described, and even defined, as extrapolative. The science fiction writer is supposed to take a trend or phenomenon of the here-and-now, purify and intensify it for dramatic effect, and extend it into the future. "If this goes on, this is what will happen." A prediction is made....Fortunately, though extrapolation is an element in science fiction, it isn't the name of the game by any means. It is far too rationalist and simplistic to satisfy the imaginative mind, whether the writer's or the reader's. Variables are the spice of life....Science fiction is not predictive; it is descriptive.