Jason Clarke

Look at a guy like Ian McKellen, who is eighty or whatever, and he's just loving his work, and you can see that in the work. That defines what type of actor you are. And what kind of people want to work with you. And whether you can do this job for a long, long time.

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.