I cannot find a link to an article I read that stated (roughly) that Krugman (?) said that sci-fi was all about economics and was the reason he became interested in economics. Unfortunately, without a link to the source I can’t verify the exact wording. I’m not wishing to put words into his mouth as it would seem underhanded. I have to admit that I am not fond of Professor Krugman (not worth discussing here), but I will at least agree that many great works of sci-fi can be seen as economic parables. That said, I do not believe that any consideration of economics is the prime impetus for writing sci-fi. I believe that economics adds flavour to sci-fi, and in many cases it is a core theme, but that isn’t what makes it sci-fi.

Classic sci-fi is based upon what-if scenarios. Spaceships, laser guns and little green men were the props necessary to illustrate the author’s chosen scenario. Sci-fi grants a freedom to go beyond the confines of physics, and everyday life, but consequently the logic within a sci-fi story is contradictory. This is also true of fantasy. Sci-fi has evolved from simple what-if scenarios to become a large meta-genre that covers a multitude of (sins) plot styles.

An interesting question would be: do all sci-fi writers sit down with a what-if scenario and then try to construct a plot around? No, I don’t believe this is the case. I think many have an idea for a plot or a character than try to create a story from their seed idea. Whether it is by intended or unconsciously decided a what-if scenario is likely to emerge.

• What if Victorian Britain actually had powerful steam-powered devices?
• What if we could go back in time?
• What if we could journey to Mars or live in the stars? (unintentionally poetic )

First and foremost, any story should have interest characters. Readers can identify with characters they like and / or enjoy reading about. The fact that a love story is set on Mars as opposed to Earth is mostly irrelevant. Readers who appreciate a love story will enjoy that aspect; they want to read about interesting characters. That’s what keeps them reading, but it doesn’t make it sci-fi. Not even setting the love story on Mars would really do that (some debate there, sure). The defining aspect of a sci-fi love story would be: what if the love between two characters can’t work because of a technological or scientific difficulty?

The man is from Mars yet the woman is from Venus, and due to different physiologies they can’t reproduce. The what-if aspect here is how can these characters life together, and should they want to try living together if they can’t reproduce? The meta-scenario of difficult love isn’t new, nor restricted to sci-fi, but the use of different planets and species gives it that sci-fi flavour. The interplay between science, the characters, and the core scenario is what defines a story as sci-fi.

On top of this simple plot there could also be economic concerns. An extension could be that the couple in the story could eventually find out that there is a way to reproduce but in order to do it would cost vast quantities of money (or resources) which are beyond their means. To re-iterate a previous statement: sci-fi can grant the freedom to take this scenario to extremes without being contradictory.

A difficult love story is familiar to us Earthling writers and readers. We can understand and empathize with the characters. Using a sci-fi setting allows the writer to appeal to extremes in order to create a grand illustration of “how can this relationship work if there are extreme difficulties?”

The appeal to extremes is also in fantasy, so naturally, there is shared ground there. I find that fantasy is less interested in the what-if scenarios but more on the themes of what makes life worth living. Sci-fi questions wants us to question existence and “why should we bother? Why do we exist?”

While fantasy doesn’t necessarily ask us “why bother?”, I think that the genre accepts that we do exist and then ponders “how could we live better?”

Caveats:

Yes, I’m simplifying but the overall direction is something I believe to be correct. The criteria I suggested in this article are not the only considerations but I believe they are common across many work of science fiction, particularly the great ones.