For instance, what is the difference between science fiction and fantasy? When I was much younger, I would have answered that fantasy was “just making any old thing up” while science fiction required an understanding of and adherence to science! (and was therefore superior). But as Thor observed that all words are made up, so too all stories are made up. The usual definition isn’t far from what younger me said (minus the hypocritical and judgmental bit): Science fiction deals with scenarios and technology that may be scientifically possible at the time written, while fantasy deals with supernatural and magical occurrences that have no basis in science.
Of course, that phrase “may be possible” includes a lot of hand-waving. Faster-than-light travel seems less and less likely to be possible as our understanding of physics has grown, yet everyone is quite happy to classify space opera as clearly part of science fiction.
It has been persuasively argued that what dictates that one novel is shelved in the science fiction section, while another is shelved with fantasy, and yet another shelved in horror all comes down to marketing. Not because marketers are trying to advance some sort of agenda, but because a lot of readers like having books offered in familiar categories. Unfortunately, the marketers (and associated persons in the publishing industry), being human, can make those distinctions on rather dubious criteria. One of my favorite authors, who writes books that cross over many genres (and has won at least one major fantasy award for a work of horror), often finds her books being reviewed as “Young Adult” simply because she’s a woman and the books tend to explore sf/f themes.
Of course, that opens up another can of worms. Who decided that “Young Adult” was a genre? It’s an age category, like Middle Grade and Early Reader, right?
It’s useful, sometimes, to talk about a specific work of fiction in reference to similar works of fiction. The aforementioned comment thread I was involved in included a discussion about why portal fantasies seem to be resurging lately, which is why I starting thinking about what portal fantasies are. I know several works that everyone agrees are portal fantasies. When I suggested that the Saturday morning live action children’s show Land of the Lost from the 1970s (I don’t want to talk about the more recent movie) might be a portal fantasy, someone else pronounced it portal science fiction.
The conventional definition of a portal fantasy is a story in which people from our mundane world enter into a different, fantastical world, through a portal of some kind. In Land of the Lost, the family on a rafting trip go through some kind of hole in space or time and land in a world where there are dinosaurs, some primates that might be precursors of genus homo, and humanoid reptileans. Sounds pretty fantastical to me! I mean the dinosaurs and primates may have overlapped a bit in Cretaceous–Paleogene boundary, but none of those primates were the size of chimpanzees, nor had brains anywhere near the size of the critters in the show. So it isn’t a time warp they went through to an earlier part of Earth’s history.
So is it a portal fantasy with some sci fi trappings? Or are the sci fi elements enough to call it something other than a fantasy?
Let’s set that aside for a moment and talk about magic systems. Because one of the things that often distinguishes science fiction from pure fantasy is the presence of magic. But some fantasies involve very strictly defined magic, with laws that seem to be as rigid as physics, and logical ways one can deduce what is and isn’t possible to do with magic from those laws. Yet, how is that different than the fictional science that underpins many science fiction stories? The author is just positing a different set of discoveries of natural law.
I described my younger self’s definition of sci fi as hypocritical because I’ve found myself, for the last decade or so, far more interested in writing fantasy. I have a couple of sci fi tales still rattling around in my collection of works in progress, but fantasy has been where I keep finding myself. And while most of my fantasy stories involve magic, I’m not one of the authors who thinks it is necessary to work out very precisely how the magic works in my universes. I have rules of my own, and I write my stories within them, but I don’t think it particularly interesting to have one of my characters (no matter how much the Mathemagician, for instance, may love giving lectures) deliver an info dump about the limitations of magic in his world. When it is important to the plot, I work it in, so that the reader understands what is happening and what’s at stake, but otherwise, I leave it to things like: dragons can fly and breathe fire, sorcerers can hurl fireballs and ride flying carpets/magic brooms, priests can smite their enemies and their blessings can cure wounds, and all of these things have costs commiserate with the extent to which reality is being bent.
And I admit one reason I don’t like going into any more detail than that is because ever since my early days of roleplaying (late 1970s, before Advanced Dungeons & Dragons, First Edition existed), the people I liked playing with least were the ones who got into long tetchy arguments about the rules before and after every single dice roll. Your mileage may vary, so if you want to write down all the laws of magic for your stories, go right ahead.
But, the fact that most fantasy stories do have rules of how the magic/supernatural stuff works, and most fantasy authors try to follow those rules and keep them consistent, I still have trouble seeing how some people can so blithely draw a strict distinction between science fiction and fantasy. XKCD had a great cartoon not that long ago around the fact that you can describe the tiny nuclear power cells in the two Voyager spacecraft as “orbs of power!” Because they are balls of a very rare metal which, once assembled, simply radiate energy for many, many, many years. Not only that, if you touch them (without proper protection), you can die! It sure sounds like a cursed magical item, such as an Infinity Stone, doesn’t it?
To circle back to the Land of the Lost–the humanoid reptiles had some very sophisticated science fictional equipment, but it was all powered by mysterious little crystals. Put the right colored crystal in the right spot and voila! A portal opens and a healing beam of energy comes down or something. Again, is that science or magic? Because, seriously, crystals?
These sorts of questions are why the late, great Jack Chalker was fond of saying, “All science fiction is fantasy, but not all fantasy is science fiction. And some science fiction becomes fantasy as our understanding of science changes over time.”