  A contentious question. My own take is that imagination is boundless, and if writer wants to explore things that could well have happened in the 'real' world in an imaginart setting - why ever not??? Any other attitude reduces SF to mere gadget spec and sci-trapolation. Not thatthese aren't worthwhle concerns that have been the hinge for many a great story, but that surely isn't ALL that SF is about, in my opinion. Writer urlLink Matthew Cheney has a fascinating essay on this topic on his blog. It's called urlLink The Geography of Imagination: Speculative Fiction as Setting . Check it out!! ! 
