John James Audubon

Surrounded by all the members of my dear family, enjoying the affection of numerous friends, who have never abandoned me, and possessing a sufficient share of all that contributes to make life agreeable, I lift my grateful eyes towards the Supreme Being and feel that I am happy.

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.