Theodor Reik

So, when you divide the world into music lovers, music fans and then those people who are just very casual about their music, it's wallpaper to them, it's elevator music, it's just the thing that's playing in the background that helps them through their day.

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.