Zilpha Keatley Snyder

Books were the window from which I looked out of a rather meager and decidedly narrow room onto a rich and wonderful universe. I loved the look and feel of books, even the smell... Libraries were treasure houses. I always entered them with a slight thrill of disbelief that all their endless riches were mine for the borrowing.

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.