Many people have tried to define science fiction. I like to call it the literature of exploration and change. While other genres obsess upon so-called eternal verities, SF deals with the possibility that our children may have different problems. They may, indeed, be different than we have been.
David BrinThe fundamental premise of sci-fi is not spaceships and lasers - it's that children can learn from the mistakes of their parents.
David Brin...where were answers to the truly deep questions? Religion promised those, though always in vague terms, while retreating from one line in the sand to the next. Don't look past this boundary, they told Galileo, then Hutton, Darwin, Von Neumann, and Crick, always retreating with great dignity before the latest scientific advance, then drawing the next holy perimeter at the shadowy rim of knowledge.
David Brin