Jacob K. Javits

You must remember, my own philosophy is that you don't belong only to yourself. You have an obligation to the society which protected you when you were brought into the world, which taught you, which supported you and nurtured you. You have an obligation to repay it.

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.