"Look, fantasy is the mother genre — e.g. Gilgamesh, the Illad, Odyssey and most religions. Sci Fi is the brash offshoot. All literature has deep roots in fantasy, which in turn emerges from the font of our dreams.
Having said that, what is my definition of the separation? I think it is very basic, revolving around the notion of human improvability."
I generally agree with this comparison. It's an unfortunate fact that most of our fantasy lit, while not conservative in any real-world-political way as any general rule, does veer into the heroes maintaining status quo against an overtly evil, clear bad guy. Sci-Fi is rarely so black and white, and though there may often be an antagonist, it can be a faceless megacorp, a cruel unfeeling society, or an imperialist alien force, as much as it could be a lone supervillain. When faced with these kinds of problems, the protagonists (maybe they're heroes, maybe they're not) are trying to undo the cruel, greedy, or uncaring status quo. Sci-Fi often starts in a relative dystopia, and the protagonist tries to push it towards a relative utopia. Fantasy starts in a relative utopia, and the heroes try to keep it that way in the face of some dark lord. That said, I think this is too sweeping a generalization and, although it could be a fair guideline to understanding genres, I don't think it can be said that it is the difference between them. I really do enjoy fantasy. But I tend to enjoy fantasy with a rebellious nature. I can't point you to a lot of fantasy literature that fulfills this, but I can point you towards roleplaying in general and Dungeons & Dragons in particular, which are traditionally dominated by fantasy. It might be my specific group of friends, or our interests, but 21st century players thrust into a medieval or Renaissance world let their modern colors fly loud and clear. They break the rules, they disrespect authority (ever have a player talk to a non-player King or other noble? They will make crude jabs, obscene gestures, and overt threats), and most importantly, they bring their sensibilities into it. They can dream of a spaceship. They will find the money, the resources, and the time, in-game, to produce things that no one in that world has dreamed up. They will find ways forward, they will break all the rules, and not just the rules of man - they will unseat gods and leave their holy thrones vacant, and they will bend reality to their whims - not unlike man bends nature to his with science. When magic is systemized into quantifiable abilities with real, known effects, it ceases to be "magic" in the traditional, mystic sense, but merely another tool, as sure as a plow, a sword, or a jet engine. Is this the same as fantasy lit, or the mainstream market for fantasy entertainment? Nope, but I don't see how you could call an RPG world like D&D not fantasy without significantly altering the meaning of the terms and unseating a lot of the baggage associated with them. And if you can do it with a group of geeks around a table with dice, I think it's unfair to assume the genre can't make it happen in literature, or even in the movies.
I've always been partial to Stanley Schmidt's definition:Basically, we publish science fiction stories. That is, stories in which some aspect of future science or technology is so integral to the plot that, if that aspect were removed, the story would collapse. Try to picture Mary Shelley's Frankenstein without the science and you'll see what I mean. No story!
The science can be physical, sociological, psychological. The technology can be anything from electronic engineering to biogenetic engineering. But the stories must be strong and realistic, with believable people (who needn't be human) doing believable things–no matter how fantastic the background might be.
No, that's kind of horseshit if the major separation is supposed to be. What about Game of Thrones? One of the major themes is the changing of regimes, from the freeing of slaves to balkanized nations. Its not a conservative series, and its certainly not science fiction. There are actually four distinct genres: Science Fiction, Science Fantasy, High Fantasy, Low Fantasy. There are further subgenres but these are most effective. The separation is the importance of mechanical explanations. Star Trek is science fiction: the show is about the mechanics a whole bunch, the warp drive is important to the resolution. Star Wars is science fantasy. Nobody cares how the force works, or how lightsabers work. The point of lightsabers and the force is to add depth to the characters and serve as a means of conveying the narrative. Its mechanics are unimportant. Lord of the Rings is High fantasy. Gandalf shoots fireballs. Why? Because he's a wizard. That's all that matters. Conan is Low fantasy. Magic has rules (chemistry.) These rules are important. More later.
Let's get one thing clear: I'm a fan of GoT. I named my daughter Arya. But "regime change" is a very different thing than "social evolution." There are no republics in GoT. Everything shifts from one king to another. To you, maybe. I've never seen a compelling argument for that breakdown, although I've read a few.One of the major themes is the changing of regimes, from the freeing of slaves to balkanized nations.
There are actually four distinct genres: Science Fiction, Science Fantasy, High Fantasy, Low Fantasy.
I think it's because science fiction investigates technology to determine how it would impact the human condition. That technology always comes from somewhere - it has a lineage, a creator, etc. Magic, on the other hand, just is. Jack Vance wrote about wizards writing spells and the like, but he also wrote about wizards genetically engineering perfect girls through the power of math. The Dying Earth is often listed as a seminal book behind Dungeons & Dragons but it's sci fi through'n'through.