Thank you
... and btw, don't forget that libraries shelve all fiction in the Fiction section. Some of them add helpful little stickers on the spine to indicate genre, but they're all on the same shelves.
It's only ex post facto that some speculation is re-categorized out of fiction and into some other area; e.g., philosophy, in the cases of Plato and More.
Finally: What fiction is not imaginative? That's why it's fiction.