Ouch, I meant “that’s my definition too” caught it too late to edit
Very blurry, since a lot of fantasy is very science-fictional in mindset, so the blurring comes from both directions. In a lot of ways a fantasy setting where magic is treated like an exotic version of physics is more science fictional than a setting with ray guns & spaceships where how everything works isn’t really considered.
And you get the occasional authors like Andre Norton, who don’t even really acknowledge there’s a distinction at all. Your opponents are bodiless spirits that can’t be harmed with material weapons? Try a ray gun. Your hi-tech secret base needs a power source? Plug some witches into it.
There are also stories where absolutely everything important to the story is magical, but the author slips in one offhand mention of a spaceship just to justify calling it “science fiction”. Apparently, at one time science fiction was considered more “respectable”, and so it was to an author’s advantage to be categorized this way.
“Gonna Roll the Bones”, by Fritz Leiber, comes to mind here, as does Anne McCaffrey’s entire Pern series.
nm..thought i’d found it…
Seems it can be read on a Kindle Fire device, or many other devices., but
not a straight forward Kindle.
The first Pern story starts with the spaceship, else Campbell wouldn’t have published it - but point taken.
On a related subject, if there’s a society that’s stayed the same for millennia, using the same level of relatively high tech (flip phones for centuries) it feels less like SF to me than a story about unabashed magic that looks at the way society changes in response to the magic.