Harry Houdini

But it must not be thought that I say this out of personal experience: for in the many years that I have been before the public my secret methods have been steadily shielded by the strict integrity of my assistants, most of whom have been with me for years.

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.