Greg Boyle

You stand with the least likely to succeed until success is succeeded by something more valuable: kinship. You stand with the belligerent, the surly and the badly behaved until bad behavior is recognized for the language it is: the vocabulary of the deeply wounded and of those whose burdens are more than they can bear.

The historical novelist has to consider what has actually happened, while the SF writer is dealing in possibilities, but they are both in the business of imagining a world unlike our own and yet connected to it.