What is science fiction? Exactly? I love this question, even more now that I have figured out the answer.
Most of us have a vague idea of what science fiction means – high tech, spaceships, wormholes, giant robots, stuff like that. If some setting doesn’t have advanced technology of some sort, it’s not really sci fi. Unless it’s a far future dystopia, which is still sci fi, but sometimes with very little technology (left). So things get confusing.
But even those dystopias are about technology in a way – they’re about the imagined ramifications of advanced technology (whatever tech led to the collapse of civilization). So the technology is at least implied.
What about something like Star Wars, though? That has advanced tech all around, but it also has this Force thing . . . and that feels an awful lot like magic.
And what about sci fi that includes technology that is not only advanced, but allows for impossible things? The ubiquitous example being any kind of faster-than-light travel? Is that still technology if it breaks the laws of physics?
To define science fiction I’m going to turn back to my old favorites, external and internal validity, revisit each, and use The Expanse to illustrate the examples. Because it’s a very cool show, and season 6 just started, and I like to jump on bandwagons.
What is Internal Validity?
Internal Validity means the narrative sets its own rules and follows them. If there are warp drives, they work in a predictable way – if they require some special fuel, they always require it. The characters don’t sometimes forget they have a warp drive.
It’s easier in a way to understand this notion by looking at stories that lack internal validity. Think of Harry Potter, where from book to book the characters seem to forget the spells and abilities they learned in the previous book, even when those abilities (time travel!) would be useful in solving current problems. Or Star Wars, where The Force can do whatever the writer wants, and there’s no apparent rhyme or reason to why some people have such different abilities than others, or even why some are stronger/weaker than others at various times. Or comics like The Flash, where there are almost always a dozen ways someone with that kind of speed could easily defeat almost any villain they throw against him, but somehow doesn’t bother.
A setting can be wildly unrealistic and still have great internal validity. If there’s a world where people have telekinesis, that’s nothing like our world. But if these abilities follow rules that are consistently applied throughout the story, we can have internal validity.
With magic systems, a high level of internal validity is often called a hard magic system – it has specific limits and parameters, works consistently, and is predictable. ‘Soft’ magic systems – the ones that aren’t clearly defined, that aren’t necessarily consistent, that don’t follow clear rules – those are the ones without internal validity.
[Important note: I’m not saying internal validity is required for a story to be good. Some stories can be weird and make very little sense in this way, yet be highly entertaining.]
What is External Validity?
External validity means the world of the story is closely aligned with our image of the real world.
To a certain extent, a story will seem more or less externally valid depending on the knowledge base of the reader. We all know faster-than-light travel is impossible, so any story with wormholes or warp drives loses a step in terms of external validity. Other failings are more subtle. I watched a movie recently where the characters were modified to ‘burn’ nitrogen instead of oxygen for fuel. The movie seemed to be trying to be externally valid, but this makes no sense to anyone who knows chemistry. Lots of sci-fi gets critiqued by experts in some field or another (“That waste disposal system would never work because they’re ignoring the gas emissions!”) but will seem externally valid to most readers.
In contrast, pretty much any time words like ‘magic’ or ‘sorcery’ are used, there’s no external validity. We all know those things aren’t real.
Something can be not-real AND be externally valid. For an easy example, take a story like The Martian – that story works very hard to use technology that, as far as we know, will be possible one day. Nothing breaks the laws of physics; orbital mechanics are researched to be as accurate as possible; there are no technologies that are completely unlike what we have today. We have every reason to think the things that happen in that book will be possible some day. Compare that to, say, Star Trek – there is no reason to think warp drives or shields are possible given our current understanding of the laws of physics.
[Important Note: I’m not saying stories with external validity are better or more important than those without.]
Do external and internal validity relate to one another?
I’m glad you asked! Yes, they do.
We believe the world is consistent. Nobody really thinks that the sun won’t rise tomorrow, that gravity might stop working, or anything of the sort. It is, in fact, a silent presupposition of all science.
So in order for a story to be externally valid it MUST be internally valid. Any internal inconsistencies will make the story appear less externally valid. I’ll get back to this later.
What does this have to do with genre?
Fantasy is literature whose setting is deliberately NOT externally valid. Period.
Does your setting have magic? Sorcery? Demons? Dragons? Vampires? Ki cultivation? Those things don’t exist in the real world; congratulations, you’re writing fantasy.
Does your setting include modern technology? Does it have vampires and necromancers living alongside cars and cellphones? Congratulations, you’re writing fantasy. Urban fantasy.
Does your setting include advanced technology like spaceships and blaster pistols, alongside magical abilities (like The Force)? Congratulations, you’re writing fantasy. Your book will probably be called sci-fi, but it’s really science fantasy. Despite the popularity of Star Wars and the Marvel Cinematic Universe (which fall into this category), science fantasy is generally speaking not a popular genre in books, and the term science fantasy is not very popular.
What is science fiction, then?
Science fiction is tricky to define because it runs along a continuum of hard and soft. At one end we have science fiction that tries to be completely externally consistent – that’s the hardest of hard sci fi. That’s books where EVERYTHING is possible, as far as we know, given our understanding of physics. I mentioned The Martian as an example. Another is The Expanse – NOT everything in The Expanse, but if you look at the human technology, leaving out everything related to aliens and the protomolecule, then The Expanse is very hard science fiction. It tries to extrapolate from current tech and physics to a more advanced, but consistent, future.
As science fiction moves away from the hard end of that continuum we see examples with more and more impossible elements. Warp drives, artificial gravity, and force fields are, in a way, no more externally valid than raising the dead or flying without visible means of propulsion.
Which raises the question: how is SOFT science fiction different from fantasy?
Science Fiction ALWAYS pretends to be externally consistent.
I think it’s really that simple. In science fiction of any kind, the impossible is explained as if it were scientifically plausible. If someone is super strong and you’re writing science fiction, they are a genetic anomaly or have cybernetic enhancements or took highly advanced steroids. If your explanation is that they sold their soul to Be’elzemoth, Demonic Patron of Muscular Power, that’s fantasy.
If you write a zombie story where the zombies are the result of a viral weapon that got released accidentally, it’s sci fi. If they are the result of a necromanatic ritual gone astray, it’s fantasy.
In The Expanse, the aliens leave behind technology that can do impossible (you could say magical) things. Create wormholes, communicate telepathically, etc. Violate all the physical laws. But the explanation is that the aliens are vastly older and have a much more sophisticated understanding of physics. The protomolecule isn’t magic – it just operates on an understanding of the laws of nature that are beyond us. The character NEVER suspect that the alien technology is anything but more advanced versions of their own tech.
Imagine a re-write of The Expanse where instead of a protomolecule, a copy of the Necronomicon was found. It contained the powers of an ancient race of demons, who had been wiped out by another ancient race (angels?) It allowed interstellar travel, infected people, and so on, all explicitly magical. Things would look different – the demonic artifacts would be covered in runes, would consume souls during their creation, things like that – but the actual abilities were the same.
That re-write wouldn’t be science fiction anymore because it wouldn’t be pretending to be externally consistent. That version would be admitting, “we’re invoking magic here.” By writing the story that they did, the authors were saying, “we’re pretending that the laws of physics actually allow for all this impossible stuff.”
There’s nothing wrong with that. I’m not criticizing AT ALL. I’m just pointing out the genre implications.
Take out the protomolecule and all its fruits and The Expanse is hard science fiction.
With the protomolecule, The Expanse is soft science fiction. [One major thing that makes The Expanse so good, and so interesting, is that the human tech is VERY hard (very realistically thought out, compared to many other examples of sci-fi), while the protomolecule very much isn’t. Usually, if a story has ANY impossible stuff, it doesn’t delve very far into the effects of microgravity on human physiology.]
If the protomolecule were explained differently – as a sorcerous book or demon egg or whatever – The Expanse would be science fantasy.
Which is better?
Nothing I’ve written here is about ‘better.’
I think there are ‘worse’ ways to handle things. If you’re writing science fantasy, do it. If, however, you write a science fantasy, and too late in the game try to explain your magic in scientific terms (make it seem more plausibly externally valid), you’ll piss people off. Don’t agree? Midichlorians. Pern.
If you’re writing science fiction, you HAVE to maintain as much internal validity as possible. If your impossible tech doesn’t follow rules, if it isn’t consistent to itself (within your story), it won’t seem externally valid (because technology, unlike magic, should be consistent). Your story will be less good.
If you’re writing science fantasy, your magic can be hard or soft (internally consistent or NOT), your science can be hard or soft (The Expanse – human or The Expanse – alien). There are more options, which allows you to tell different sorts of stories, but again, neither better or worse.
Footnote: What about The Hybrid Helix?
Like most (maybe all?) modern superhero universes, my setting is science fantasy.
Where my writing differs from others is this: my magic is hard magic (high level of internal consistency). My science fiction elements are hard-ish sci-fi (only a small handful of the purely technological things are impossible given today’s understanding of physics). Overall, I’m aiming for a LOT of internal consistency. Other examples of science fantasy care about that less (Star Wars and major comic book universes, I’m talking to you).
That isn’t to say that my stories are better, just that they’re better in ways that matter to me, personally. I like internal consistency. A lot.