# Why Would Aliens Enslave Humans?

Often in science fiction, we see aliens enslaving humans for one reason or another. This is a trope I'm attempting to repurpose, but before I go any farther, I'd like to ask: what possible motive or means could aliens actually have for enslaving humans, particularly enslaving humans and taking them to labor on other planets?

I've been using historical examples of New World slavery as a model, but I'm curious as to whether or not this is realistic. Surely the contact between Europeans and the North and South American peoples would have felt "alien," as would have the great differences in technology, but I'm wondering if, given the vastness of space, it would actually be economic or even conceivable in the first place for aliens to do to humans what the European explorers and conquistadors did to Americans.

It's important to me that I find a way to realistically portray such a scenario or to not portray it at all if, in fact, it's not realistic, even though it's been done many times before.

I know it's a broad question, so I'll summarize: would there actually be any economic incentive and technological means for aliens to enslave humans, or would the vastness of space and drastic differences between our species dissuade them from it?

• What is the incentive for the aliens to get to Earth, in the first place? – jose_castro_arnaud Apr 11 '17 at 23:37
• @jose_castro_arnaud, I'm open to suggestions, but I've been operating under the assumptions that the aliens, like us humans exploring the New World, are exploring for exploration's sake, and that they continue to do so when they find anything profitable or interesting. – C. S. Wright Apr 12 '17 at 2:51
• Differences between the species would make it more likely rather than less or so I'd imagine. Judging by our own experiences- the more different something is- the less human you have to treat it. – Friendlysociopath Apr 12 '17 at 4:12
• Strictly slavery? Or is it just that humans are tasty? – Roger Lipscombe Apr 12 '17 at 10:39
• A1: "How are rations?" A2: "Low. Fuel too. We must restock, and soon." time passes A1: "This planet will do. Take what we need." A2: "This may take a while." A1: "Use the natives. Their numbers and knowledge of this world will expedite the process. Bring the strongest among them with the cargo - we will need them if we are to maintain it all properly. Now go. We cannot afford to further delay our mission." --Et. al. We are a means to an end. – OhBeWise Apr 12 '17 at 14:26

Humans are particularly suitable for a certain kind of labor that the alien race is not:

• As methane-breathers, mining the vibranium on our oxygen-rich 2nd moon has always proved too difficult and too expensive. But look at this race of oxygen-breathers we found, good thing interstellar slave ships are cheap!
• Since our race's transcendence into pure mind-in-a-floating-jar, we have relied on machines to handle all physical and manual tasks. Unfortunately, we discovered too late that our repair bots can't actually repair themselves, we need someone with fingers to do that for us.
• On our planet, it was beetles that became the most intelligent species. We've always succeeded by working hard together, but it takes 400 worker beetles to move one medium-sized rock. If only we had some tall brutes with muscular arms...
• Our cloud-based species can't handle the dense atmosphere of the rocky surface many miles below. If we want to extract the valuable unobtanium ore there, we need a type of worker who can.
• This "sportball" we've seen on interstellar transmissions is very interesting to us, the speed and reflexes shown is amazing. What if we had our own league of humans to play sportball?
• The spaceships we stol... I mean contracted to purchase from species 9462 have service compartments that our 15-foot tall adults can't fit into. We need to enslav... I mean enter into an extended service agreement with a smaller species of repair engineers.

As an analogy, don't think of how humans have enslaved each other, think of how human use other species:

• We ride horses and camels
• We hunt with hawks and hounds
• We send messages by carrier pigeon
• We use mules and elephants to carry burdens
• We use oxen to pull plows
• We race thoroughbreds and greyhounds and ostriches and hamsters and cockroaches
• We are entertained by tigers and dolphins and trained monkeys
• We keep all the above and more as beloved pets

If those species were intelligent, how might they use us?

• I love this answer. As long as the economics (including time) of interstellar travel can handle it, this will give you all the reasons you would ever need: simply customize to your specific aliens. – Ghotir Apr 12 '17 at 15:58
• Fifty quatloos on the newcomer! – Harper - Reinstate Monica Apr 12 '17 at 17:00
• Certain parts of us are also considered a delicacy – BlueRaja - Danny Pflughoeft Apr 12 '17 at 20:20
• To add to your final list: we use dogs to sniff for drugs and to find tornado/avalanche/bombing survivors. We can build technological sniffers but none that are as cheap, reliable, versatile, accurate or as easily trained as a canine. Even advanced technology often falls short of basic biological functions, so an alien race being good at spaceships doesn't necessarily mean humans are worthless or worth little just because we're bad at spaceships. – Asher Apr 13 '17 at 16:14
• @Asher: The species does not need to be blind. They might just see at a different part of the spectrum. Or maybe the species is colour blind, and our colour vision just gives us a superior ability to distinguish certain chemicals/find certain minerals, as we can easily spot the red spots in a blue surrounding, while the aliens would just see some grey mess. – celtschk Apr 14 '17 at 13:39

You are misunderstanding the nature of our abductions of your people. We are not enslaving humans. That's gross! Did you really used to do that to your own species?
Maybe you aren't as intelligent as our advanced scouts reported. "Mostly Harmless" is probably too generous a category for you. I will have to look into getting you reassigned.

But back to your question. We don't take you from your home world for our own personal gain. We do it for the sake of the universe. Intelligent life is rare and your species is perfect for those miserable middle orbit planets which are too cold for any of the metal breathing species and too hot for the gas giant hives. You actually like planets with liquid water on them. Do you know how rare such an affinity is? No, obviously you don't or you wouldn't be wasting your time enslaving each other.

You are a precious and rare creature. The universe has millions of planets which are just right for you and are wrong for all the rest of us. If we are ever to raise the average intellect of the universe above approximately zero, we need you out on all those ugly blue worlds; thinking your thoughts and dreaming your dreams.

We are not enslaving you. We are helping you and ourselves in the only economics that matter... the commerce of our minds over the mindlessness void.

• Not bad, @Henry Taylor. Cultural, educational, and cultural justifications of a similar nature would have been used by some (not all) explorers and missionaries of the New World, as well. – C. S. Wright Apr 12 '17 at 2:54
• Someone's been reading the Uplift Trilogy :) – jwenting Apr 12 '17 at 13:54
• @jwenting, David Brin is awesome! I never claimed that any of my answers are solely my own. I steal from all of the best! – Henry Taylor Apr 12 '17 at 15:09
• @FuriousFolder. The American Dodgeball Association of America! – Mad Physicist Apr 12 '17 at 16:16
• This tangent has been approved by the Department of Redundancy Department. – Monty Harder Apr 12 '17 at 18:07

The question you have to ask yourself is this: does slavery make money, in whatever economy they have?

If the answer is yes, then that's reason enough, barring ethics issues.

is labor cheaper than tech used to achieve whatever money making thing they're using the labor for?

does the culture of the aliens serve to make humans a sort of pet and/or pleasure slave? If they are too different in type for the latter, then an economy wherein humans and other aliens are treated as curiosities for the wealthy to own, especially if the aliens believe us to be lesser--that could make sense.

would there actually be any economic incentive and technological means for aliens to enslave humans, or would the vastness of space and drastic differences between our species dissuade them from it?

The answer is yes, there could be an economic incentive, and yes, this is broad. Anything from mining to farming to servant labor, or an "exotics" market (kind of like the illegal exotic pets market). As for technological means, just put an explodey collar or implant on said humans, or something that causes pain or pleasure.

• to clarify, the aliens are humanoid (so at least somewhat similar), and my plan was to have them use the humans for mining purposes. – C. S. Wright Apr 12 '17 at 2:59
• @C.S.Wright if they have interstellar transport, surely they have robots that are better at mining (tougher, better in tight spaces, ...) than humans could ever be. +1 for pets/entertainment – G. Ann - SonarSource Team Apr 12 '17 at 15:40
• @G.Ann-SonarSourceTeam unless it's cheaper to import buy & sell humans than it is to manufacture robots. Depends on what they are mining. Also, they might need people to actually man the equipment--awesome space travel doesn't = cheap AI. Sure, they might have the tech, but man, the shipping costs to get it there...way cheaper to use humans till they wear out. There's so many of them and they breed so fast... – Erin Thursby Apr 12 '17 at 17:45
• @C.S.Wright and after they're worn out they make a nice afternoon snack... – jwenting Apr 14 '17 at 12:51

## Aliens enslaving humanity for economical reasons is utterly unrealistic

Technology that makes frequent travel between stars economically feasible is almost beyond our imagination. Given physics as we know it, faster than light travel is time travel and breaks causality. Slower than light methods that we can imagine now require ungodly amounts of fuel to transport tiny amounts of cargo. So, it is fair to say your aliens are very advanced.

Now let's get back to today's world. How many jobs do you think humans will be able to do better than a robot in 2025, in the real world? Mining, agriculture and manufacturing are already mostly automated in industrialized nations; self-driving trucks and robot surgeons are around the corner.

Conclusion: it is utterly unrealistic for a civilization to have unimaginably advanced technology that enables economically feasible travel between stars but be so far behind in robotics that they cannot make robots that are more efficient than humans for labor.

## Therefore, their reasons for enslaving humanity must be purely irrational/cultural

The gods command it, they enjoy enslaving sentient beings, they are enslaving us for our own good, etc.

• as much as I hate to admit it, you've touched on the real dilemma of my question. I'm going to be obstinate and keep looking for at least a semi-reasonable solution (perhaps irrational religious or cultural reasons as you suggested), but I appreciate your honesty. – C. S. Wright Apr 12 '17 at 21:50
• I's a stretch but what if the aliens had limited technology and social development, but were able to travel vast distances at seemingly impossible speeds? If for example (depending on how fi you like your sci); you have a highly evolved leviathan, a living ship capable of FTL travel, that some brutish aliens have accessed either thanks to some other unwitting sentient race or because this creature evolved on their own world, those aliens of limited empathy could travel the universe being all mean and enslaving folks for practical proposes and/or their amusement. – Brent Hackers Apr 13 '17 at 8:23
• There's many stories where AI is not approved of; it's simply too dangerous, possibly with historical evidence about why. – prosfilaes Apr 13 '17 at 8:51
• +1 because I was going to give this answer. It's also the rationale for interstellar military conquest. – EvilSnack Apr 14 '17 at 2:11
• @Solanacea Why is an interstellar spaceship AI? Voyager 1 is arguably the first Earth object to reach interstellar space and is not remotely intelligent. Large aircraft carriers and nuclear-powered submarines, large long-term people containers, were originally built with pre-1980s computers. On the other hand, anything that has free movement and sight (like self-driving trucks and robot surgeons) requires AI, at levels we're currently working on mastering, and that's easily a line too far for people who fought a war against AI. – prosfilaes Apr 14 '17 at 22:57

Think of the humans as being like cattle, it's not slavery as they are not enslaving their own people (maybe they are, but the humans aren't being enslaved). In the same way we can justify dominating other life forms for our own benefit, they would be able to use that same reasoning. It's no more immoral than our farms are, really, and just like how we gain benefits from taking advantage of other species, those same reasons could easily apply to aliens taking advantage of us.

Perhaps humans are more able to survive in certain environments than the aliens are, and so it's cheaper for them to get us to harvest certain resources for them, than to develop technology to allow them to do it themselves.

Perhaps our problem solving abilities are more fluid than theirs, they might have a very rigid society without the ability to innovate much, and so they are taking advantage of how we think.

Perhaps they don't have the alienpower to perform everything they want to do, so they use manpower instead for their simpler tasks.

• Alienpower. Nice. – Mad Physicist Apr 12 '17 at 16:34
• "Perhaps our problem solving abilities are more fluid than theirs" Reminds me of an episode of Stargate. Using a small, controlled explosion to propel bits of metal is utter insanity to a galaxy that uses nothing but energy weapons. – UIDAlexD Apr 13 '17 at 14:53

There are many reasons for why enslavement makes sense but it is difficult to tell conclusively why, without knowing the nature of their reality / situation.

1.Economical

• Labor
• Automation has hard limits, and general Artificial Intelligence is impossible OR the Aliens think / believe this.
• Said aliens have limited breeding ability, and a massive empire. Sure you can automate a lot, but you still need workers.
• Humans are Super Duper special, able to work on planets that said Aliens cannot.

2.Political

• It makes sense from some political viewpoint
• Uplifting / The Caring Big Brother
• Manifest Destiny

3.Religious

• DEUS VULT!
• The Korbloxian’s Burden

4.Militaristic

• They need soldiers for the meat grinder, see labor requirement

5.Technological

• Our genes and ecosystem give a whole new playground for them.
• Humans make really great crash test dummies

6.Goldie Locks

• All galactic life evolves in certain biomes, making only certain planets inhabitable.
• They want our planet, and well we were already here

7.ROFLMAO

• Humans are SOOO FUNNY
• Humans are sexy smexy
• Humans are pets.
• "Automation has hard limits, and general Artificial Intelligence is impossible OR the Aliens think / believe this." Or strong AI is outlawed out of fear of the AI apocalypse. At least with those alien life forms of Terra, you know their limitations. – celtschk Apr 14 '17 at 13:47

Consider an advanced Alien civilization at the height of its powers, interstellar travel, the ability to automate any task, everyone living in a post scarcity society.

At some point in the past things went wrong (through resource shortages/war/pathogen/cultural change/rise-of-the-machines or whatever).

Now you have later generations struggling to survive with tech they don't fully understand, it might be easier/simpler for them (or for factions of them, rebels fighting the selfish & sufficient elite) to enslave intelligent creatures such as humans to farm/mine/fight for them than it is to try and understand the machines they use.

My two cents.

• a good two cents. I'm planning on having a kind of technological recession anyway, so this helps. – C. S. Wright Apr 13 '17 at 14:07

If there were only a few aliens on Earch, it would be worth enslaving humans if they wanted to get things done on Earth.

Let's say that traveling between stars is expensive and time-consuming, so they can send only a small population of aliens. Let's say that they are interested in extracting resources and sending them home on automated transports or they want to construct industrial facilities on Earth. Unless they have the capacity to quickly produce sophisticated robots that can do any necessary task and make good autonomous decisions, they are likely to want to enlist the local population to get things done.

Now getting the local population to do things for you doesn't have to involve enslaving them, but that's probably the easiest way for a technologically-superior, non-commerce-oriented species to achieve results. Humans aren't likely to voluntarily devote large parts of their economy toward serving the aliens unless there are some really good things the aliens have (and are willing to) to trade (like technology).

If a very results-oriented aliens species comes along, they are likely to take care of business in the most expedient way possible, which may just involve enslaving everyone. It might just be easier for them to do so than spend a lot of time haggling with the local populace or maybe haggling isn't done in their culture. A small group of aliens with some fearsome weapons could do so, particularly if they enlisted some humans to help them. History shows that there are plenty of people who will do some terrible things for favored treatment or to just get the chance to oppress their enemies.

Results-oriented aliens probably wouldn't necessarily be interested in controlling every aspect of their enslaved humans lives. The humans could live pretty well or live terrible lives. It wouldn't matter as long as stuff got done. Chances are they would delegate the human management to their favored group of humans and only intervene when the "overseer" humans couldn't keep the rest in line or when production slowed.

As you pointed out, there are strong analogies to the early Spanish conquistadors. They came from far away, had better technology (but could still be defeated because they were far outnumbered), and had a very different way of thinking than what the Native Americans were used to. They were friendly at first and then struck by surprise, catching the natives off guard. They also enlisted the help of other natives to help them conquer. Cortes, for example, enlisted the help of various groups against the Aztecs. Those groups jumped at the chance to get revenge on their hated enemies. Cortes couldn't have defeated the Aztecs otherwise: the Spaniards were too few.

The results-oriented Spanish were looking for precious metals (mainly gold and silver) to ship back to Spain and enslaved many of the Native Americans to get it. The natives were the labor that was necessary to get the resources, since no other method was available. They brutally enslaved the natives, but I think that if they though they could have achieved better results with a more lenient enslavement, they would have done that. The important thing to them was wealth and they were taking any means to achieve that.

So I do think that aliens with a certain way of thinking could think that it would make sense to enslave humans, if travel between stars is long expensive, but Earth has resources valuable enough to make it worth the trouble. Sending back automated cargo ships full of resources on a regular schedule would still be worth it, even if it would take centuries for those resources to reach their destination. Once the contents of pipeline started flowing at the destination, it wouldn't matter much how long it took to get there.

• great answer. Obviously, it largely assumes that alien enslavement of humans is taking place on Earth rather than some exoplanet, but a lot of your other points square nicely with various details of the story and world I'm designing. Thanks. – C. S. Wright Apr 12 '17 at 21:39

It depends on what kind of technology you want to give your aliens.

IF they need weeks or months (or more) of travel, to come to earth, then you must figure something the humans can do better than the rest of your alien species. That's reason enough for slavery - not always economical affordable, but a necessity.

IF they can appear instantly "wormhole-like" in the outskirts of a solar system, then you can have as many reasons for slavery as you want, no matter how mundane. The short time of travel will make them financial affordable

• the aliens are coming from a relatively far distance and would take at least a year or so to get from their world to ours, if not longer. – C. S. Wright Apr 12 '17 at 21:24
• @C.S.Wright if they come from so far away, how do they know about humans? were they here before scouting? why? when? how? what do they know of us? why do they need us? labor? organ donors? sport hobbies? gladiator arenas? collection items? – andrew Apr 13 '17 at 4:55
• they encountered us by accident in the process of exploring and searching for planets worth investigating (i. e., ones with possible life). They took us as slaves for the purpose of mining back on their homeworld. – C. S. Wright Apr 13 '17 at 13:49

In Eric Flint's Jao Empire series (first book downloadable for free here), the Jao enslave other species because they are at war with a genocidal alien species. That enemy would destroy all life on every planet anyway, which would be kind of a waste. So it makes sense for the natives to instead live and help the Jao's war effort. What doesn't make sense is for the natives to be doing anything else that isn't helping the war effort.

Also, the Jao are aliens, with alien ways of thinking. To them, there is no higher calling than being "of use", particularly in the war effort against the enemy who are trying to cleanse the galaxy. So they are really doing the aliens they conquer a big favor by giving them the chance to "be of use". If those aliens (like humans) can't understand that, they must be dumb animals or something.

I'd also point out that this isn't too far gone from the historical "White Man's burden" theory, which held that white people were so superior to everyone else in the world, that it was their duty to those people to conquer them and force the superior culture on them. So you could go with the "Bug-eyed Alien's Burden"

• so I ought to introduce an ethical dilemma? Good idea. – C. S. Wright Apr 12 '17 at 21:40
• @C.S.Wright - Note that the first book in the series (which is the one that goes most into this exact ethical issue) is available for free download from the Baen Free Library – T.E.D. Apr 13 '17 at 0:09

Humans unlike every other form of life on earth are intelligent and have dexterous hands which can be put to numerous forms of labour that no other animal on earth no matter how intelligent could perform. So physically we are more versatile and useful than every form of life we know about. Mentally we can be taught to do things, AND figure out how to do things ourselves.

So we'd be prime slave material as workers to enterprising aliens with a labour shortage. And that's not including our value as entertainers.

• I suppose the question would then be: why would the aliens make slaves of us rather than themselves? – C. S. Wright Apr 12 '17 at 21:26
• Any number of reasons I can think of, able to survive in a certain atmosphere or pressure, lack of actual aliens to enslave in far flung corners of the universe. Something as simple as 'Slavery is illegal' while utilising animals is perfectly OK. – Kilisi Apr 12 '17 at 22:00
• I like that last one particularly. It would be very similar to how us humans justify (whether rightly or wrongly) many of our otherwise questionable endeavors. – C. S. Wright Apr 12 '17 at 22:09

One problem with the theory that they want to steal our resources (this being an obsession on the part of film makers...) that everyone just seems to forget, or they just like to ignore the facts of our solar system: there's SO much more of any resource/rare earth metal, etc in the asteroid belt and the Kuiper belt they wouldn't need to bother enslaving anyone or taking anything from Earth, destroying things in the process when they can just grab vastly more of any such resource right from any asteroid (if they want metals of some kind) or comet (should they need lots of water). Why bother enslaving anyone - which would be very costly and time-consuming, when they can just grab whatever they want from out there (from any asteroid belt in any star system for that matter)!? And let's face it, humans are not as efficient as they like to think, quite the opposite, many are as lazy as they come. Why bother with organic beings when you can just send a robot to mine something?- A lot more efficient, doesn't require food, water, sleep, a bathroom, etc, and you give a command and it starts to do what it is you want it to, not to mention it doesn't get tired, will only need the occasional repair. They would have to be unfathomably stupid to bother with all that when they can just grab things from asteroid belts!

(***there are many star systems that have them all around the galaxy - no need to interact with any other lifeforms to get the stuff they need)

• I guess the question would be whether or not robots could actually hold a candle to intelligent life so far as labor and ingenuity are concerned. Still, good points. – C. S. Wright Apr 12 '17 at 21:23
• I was referring to robots that are not AI/ASI, merely the kind of robots that are much like the ones that build our cars for ex., by performing those tasks that cannot be undertaken by humans. I imagine such aliens might have either found a way to keep their robots from achieving any form of consciousness, or they've merged their minds to artificial bodies, in which case they could just continue building robots to perform tasks such as mining or they could build different types of "bodies" for themselves and transfer their consciousness into them to perform any task they wish to, anywhere. – Ebony Cavanagh Apr 12 '17 at 22:35

After reading all previous answers, the obvious one seems to have been left out. I imagine the driving reason for exploration is the need to increase economic growth. Species X finds planet Earth and due to their own high standards of civilization, they would never even think of enslaving an intelligent race, even if so marginally intelligent as us apes.

So instead they land and start to sell trinkets for big bugs, take out mortgages, buy out major companies, put everyone over their ears in unimaginably large debts, then require you to consume whatever leftovers their economy produces and need markets for.

After 2 weeks of overconsumption, the entire human race is by law employee of the interstellar X company and forced to work for life ('why, do they really only last for like 80 years?') to pay off the debt they were lured into. Slavery, no such nonsense, too much below accepted standards.

Before soon, large plots of Earth are being sold to extravagant ETs as 'second houses'. Within 10 years, the human species is determined to be 'on the brink of extinction' and, for its own sake, deported massively to an underground base on Mars, where the, by then, last 20 remaining women are kept in closely guarded quarters for the Interstellar Collection of Curiosities for extensive breeding. Unfortunately, species X only included 2 males, one of which is homosexual and the other transgender and infertile. They all seem so much alike.

And on to the next planet, because the economy needs to grow.

It's not really for economic gain. The alien culture is way beyond that. No, it's science: They are studying humans by putting them into different situations. For example, they study how humans behave when they are forced to mine minerals from planets; how they organize, what it takes to keep them from revolting, what strategies they employ to make their work easier, how much work they can do before they break down … sure, the mining itself could be done much better with machines, and indeed, that's how the bulk of mining is done. The human mines are not really about minerals (even though the humans in that experiment are told that), they are about studying humans.

The same is true about the other places where humans are put to work, Of course they won't tell the humans that there's not really a need to steer cargo spaceships though asteroid fields, as there are both automated cargo ships and safe routes. But by sending human pilots through those fields you learn a lot about how they react to dangers and learn to avoid them.

And humans are perfect for this sort of research, as they are intelligent enough to show interesting behaviour, but still stupid enough to actually believe those ludicrous scenarios they are put into.

• Great point, @celtschk. This fits really well with the setup I'm working with. – C. S. Wright Apr 17 '17 at 16:57

Thucydides says nations go to war for Fear, Honor, or Profit. That's a really good lens for looking at "Why does [group] do [thing]?" and is especially apt here.

Fear: Aliens enslave humanity to keep them from doing something. Maybe humanity is prophesied to destroy them, maybe humanity looks exactly like a predator on their homeworld. Regardless, humans are scary to aliens, and they need to contain or control us somehow. Might as well be slavery.

Honor: Aliens enslave humanity because they feel it is right or good. Maybe they have religiously-granted dominion over all the beasts of the galaxy, maybe they are deep in the grips of the Green Man's Burden. Maybe humanity is the secret progenitor race, and aliens are only now finally able to break free of our ancestors' grasp, and show us their strength. Regardless, enslaving humanity is some sort of moral imperative.

Profit: Aliens enslave humanity because they want stuff, and maintaining a slave race is an easy way to get it. Maybe they can't mine precious gold in our toxic atmosphere (Psychlos...), maybe human slaves are inherently a luxury good. Maybe hey just like watching the monkeys dance.

Note that these aren't mutually exclusive either, and reality is rarely so clear-cut as to have one cause per effect. So mix and match! Humanity is prophesied to destroy alienity, so they are avoiding that by training us into good galactic citizens by forcing us to write enormously-profitable screwball comedies.

It all depends on how you build your world.

If space travel is cheap and reasonably fast, and differences between races are not huge, enslavement could go in a scenario similar to how it went here on Earth.

If, on the other hand, sending any passengers through space is very expensive, or if creating livable conditions for them is too much of a task for the aliens, enslavement would indeed lose its point.

There are other topics that you would probably need to address, like antislavery feelings among the aliens (or lack of any such feelings), as well as how imported slaves can be better than robots.

• good points. The aliens in question are humanoid, so now I just need to pin down whether or not it's economic and "ethically acceptable" (for them) to pull this whole thing off. – C. S. Wright Apr 12 '17 at 2:57
• It doesn't have to be ethically acceptable throughout their society. In fact the enslavement may be done by an outlying faction or just specific "immoral" individuals if your story lacks tension from other sources. – Mad Physicist Apr 12 '17 at 16:35
• Even economic benefit can be indirect. Think lab rats. They do no useful labor, but by breeding fast relative to humans, they can allow us to do research that may or may not have economic benefit in the future. – Mad Physicist Apr 12 '17 at 16:36

If an alien civilization has the technology to cross the interstellar void (i.e. at least fusion), it's safe to assume the have comparable knowledge in genetics and bio-printing. Hence, they'd be better off picking up one of your fallen hair, analyzing the DNA, transferring the data at light speed (e.g. radio) back to their homeland, and manufacturing as many copies of you as they need on the spot.

If they intended to maintain the human population long-term, they'd probably gather a few hundred samples, plus other parts of the biome we rely on (plants, animals, bacteria).

Also, unless they can travel faster than light, they'd probably want to send to earth a robot probe that would get here much faster, being able to handle higher acceleration than organic beings (assuming the aliens are organic).

• Yes, I was tempted to add that, if FTL travel existed, it might actually be easier to ship you off-word. – Sebastian Rosloniec Apr 12 '17 at 16:42
• However, if the destination is not exactly earth-like, it's unlikely to be easier to terraform the whole place to accommodate you, instead of engineering a better adapted version of you. – Sebastian Rosloniec Apr 12 '17 at 16:43
• clever idea. To clarify, the aliens are (necessarily) capable of near-lightspeed travel (maybe FTL as well, but the plausibility of this is a whole other question), and the planet they take the humans to is, in fact, earth-like. – C. S. Wright Apr 12 '17 at 21:46
• Both FTL and near light-speed are probably only accessible to a Kardashev II or higher type of civilization, which would treat humanity as a colony of bacteria on a spec of dust. Nonetheless, let' suspend disbelief for the purpose of story-telling and assume they're as advanced as the aliens in any movie who perhaps got the tech as a gift from another civilization. tbc... (comment length limit) – Sebastian Rosloniec Apr 13 '17 at 19:20
• The other planet's atmosphere being Earth-like would require a biosphere being there for a good while (3bln years in case of our planet). If the abductors' biology is similar to ours, they could use us as genetic cannon-meat to evolve immunity to all those microbes, and then copy the relevant genes and colonize the place themselves. Meanwhile, we'd build the entire infrastructure for them so when they're ready they could just step in as gods and have us serving them. – Sebastian Rosloniec Apr 13 '17 at 19:20

At the scale of interstellar trade or exploration, there are a few reasonable situations.

If there is FTL, physics is extremely strange and not at all like what we expect. A reality check in this case is difficult.

So, assuming no FTL, interstellar trips will involve tiny self-replicating hardware "seeds" that grow into a civilization. Machine intelligence, in short.

Now, it may turn out that organic or hybrid intelligence is more efficient than machine intelligence at a myriad of tasks, or that uploading "real" brains to an emulation layer is the most efficient way to get intelligent actors in the machine.

I will assume that growing intelligence in a machine may be wasteful, because real intelligence requires something as complex and rich as reality to grow, while maintaining and training existing intelligence is much easier.

In this case, the aliens could enslave humans for brains. Humans consume a biosphere, which doesn't use much in the way of resources that a star-wisp civilization needs to replicate, but still generates intelligent actors.

So the star-wisp civilization doubles itself a few dozen times in space, builds an invasion force, and invades the planet. There are only a few true intelligences, but a myriad of "smart bots".

They descend upon Earth and harvest our brains. Maybe they start with voluntary uploads, but given how weak our defences are decide that it is more expedient to just upload almost everyone and discard the unsuitable. A breeding population is left behind to provide for further harvests.

The generated intelligences are modified and trained to do tasks and have loyalty furthering the production of starwisps, solving certain categories of problem that require true intelligence.

The orbital civilization bootstraps up to somewhere between K1 and K2 level, then starts launching further starwisps. It is a race, because there are other starwisp lineages that are also spreading out, and the faster you get 1 or 2 out there the more likely you get "ahead of the curve"; and if behind the curve your starwisps arrive in an already colonized solar system and your lineage dies out.

Once this first wave is complete and a few dozen starwisps are sent out, the solar system fortifies against other starwisps arriving and starts a colony of the original aliens. As noted, the most efficient way to produce new intelligences is to grow them organically, so biospheres are built, artificial bodies are created, machine intelligences downloaded, and children are raised.

Enslaved human minds remain useful during this period, but are reduced in importance as more and more of the intelligence requirements of the hybrid civlization are provided by their own biological creatures. Terraforming of planets is started (as they are more robust than orbital habitats). Once a few stable biospheres on planets or moons are robust and up and running, the terraforming of Earth begins.

This results in the extension of the human lineage, but by this point they are no longer of economic use to the aliens.

One big advantage of slaves over robots/automation is that they are self replicating and can produce their own fuel. Imagine you have a place rich with a rare resource your race needs, but the environment there is marginal. Your people are much to enlightened/fat & lazy/... to brave the harsh environment, so you drop a seed colony of humans with rudimentary equipment to extract your resource, food to last a year, and seeds (maybe a few farm animals) and farming equipment. They either build a mining outpost or die (strong motivation).

This place could be another planet in your slaver races home system (or another system if they have FTL) or just an isolated and harsh region of their home world (think Botany Bay).

You come back periodically, pick up the resource(s) they've extracted and if they've done well give them their rewards (luxury goods/ recreational drugs/...) or if they've done poorly in their production of your resource(s), you punish them (public executions/withhold their recreational drugs/take the T-Bird away/...).

It's not exactly slavery, but the end result are the same. With some good propaganda, you could convince them they're free and part of some noble endeavor.

NO

The Alien race starts out as a planetary civilization, with tech similar to ours, they expand and develop better tech all round, build space elevators, orbital habitats, mine asteroids. With a population in the trillions, and vast swaths of space solar panels to produce antimatter, the aliens launch their first interstellar probe, its a small flyby mission. Populations expand further, tech booms, artificial intelligences controlling robots produce almost everything, nanotech lets most things be created atom by atom. Probes reveal intelligence on earth.

To get any humans, the aliens would need to build a spaceship capable of supporting humans for many years, and making a return journey at relativistic speeds. They would have to work out what humans eat and breathe, enough biology and medicine to keep the humans alive over the many year journey, decode human language,build a huge spaceship, stop the earth being fried from the exhaust, (actual problem) and stop the human from going mad with boredom, killing themselves or damaging something important. And in just 60 years from the start of the project they have a human, after a huge civilization wide effort.

Now you have to train the human to do the vitally important task while not giving them the tools to rebel or damage anything important, given that they have no understanding of your tech or culture and probably wish you dead.

Even if you managed to abduct much of humanity, what use would they be? Your toddlers have a far better understanding of your world and culture, they need to be kept in a different atmosphere than you, and your advanced robots do all the work anyway. The aliens outnumber humans nearly 1,000,000 to 1 at this point so humans aren't abundant enough to be cheap labor.

There is actually a rational reason for aliens to enslave us. Meat is not better than machine at doing manual labor, especially our meat, but! Our minds are very, very effective at certain tasks, especially reflex and basic reasoning-based ones. We can outpace all AIs, so far as we've created here on Earth, in abstract reasoning, unfamiliar or new logic, and definitely intuitive thinking. But let's say that your aliens are so advanced that they don't even need our minds; their AIs and pets are smarter than us.

We're still useful.

An alien race that advanced could, theoretically, look at our brains and say: "Huh. Neat. Let's use that." Then, summarily genetically engineer us to be brain-producing biological machines with a sole purpose: pumping out modified human brains to be used as computational nodes or whatnot. They could even do the same thing with the neural networks of giant pacific octopuses.

But let's say the aliens have it all figured out even there, and don't need our inferior neural networks, at all. We're still useful, for one thing: exploration. For any alien species that advanced, our planet would be pretty useless for anything except maybe a bit of ore, but even then, what trouble it is to extract. But a curious alien species would want to know. What's there? What's alive there? Earth is incredibly diverse in biome and biomatter. So, let's use the humans to explore. Expend minimal resources and send a single ship: have it infect the human population with some kind of retrovirus or drug or something else that brings them under our control. Make them want to explore. Educate them on how to do it right. Press the "go" button, and have the ship move on and do other important things.

There's many other things our tiny brains could be useful for, and our tiny labor abilities, especially if the aliens consider it a matter of mere curiosity or simply don't care how fast it gets done so long as they don't have to waste their own time or resources. It's just foolish to focus on merely the kinds of slavery we humans have inflicted on other humans; as the world changes, what's profitable changes. Slaves for manual labor wouldn't be profitable or competitive in a post-scarcity market or one where robotics are so absurdly advanced. At any rate, that's my answer. :)

Aliens may enslave or destroy us for the greater good of the planet. Actually, it is possible for the aliens to think that we are a threat to most of the other species on the Earth. Aliens may see us as an evil, which is ruling a small planet with their only strength, brain. Our population is high, we are consuming more than what we need, we are depleting a lot of resources, we are polluting the Earth and we have destroyed the balance of life on Earth. They see Earth as a moldy cheese, they enslave us (as slaves) to destroy us, with the least regard to our lives and well-being (just as we do to ourselves and other species on the planet), to get rid of that mold and to make the cheese better for others.

Another possible scenario: having investigated our expectations they found that this is what we want them to do to us. This is subconscious, they know for sure that there is no way to explain to us that this is what we want. And they also know that we really need it.

This looks very unrealistic at first glance, but given suspicious popularity of the theme in movies, etc. makes me think that this might really be a massive subconscious desire of humans en masse.

My personal opinion is that it makes little sense for any aliens to enslave (or exterminate) humans.

### Irrational reasons

Essentially any civilization capable of getting here (using realistic spacecraft) to enslave us already has all the resources and capabilities in their own solar system that they ever hope to acquire from us.

The only way you can make it worth the time and effort to come here is if their motivation isn't rational (e.g. religious reasons) or you make space travel ridiculously easy - for them (we may still be stuck with "realistic" space drives).

Alternatively, if your slaver aliens are biologically oriented, then they may use spacecraft designed by other slave species. If that species is dying out or revolted, the slaver species may require new "clever monkeys to tinker with their flux coils."

In a realistic scenario, I would think they'd only need breeding stock and wouldn't have much interest in enslaving the whole planet. But if there was an ongoing war and they needed helping hands quickly, maybe enslaving the whole planet would be the fastest method of acquiring the necessary work force.

### Forward staging or manufacturing base

If it were just civilizations going about their business, then it would not make sense to use this section. However, if there were on-going hostilities or the threat of such, then the aliens might wish to stage from a system that wasn't their home system.

If they flew ships from their home system, their enemy might figure out where they originated.

One advantage of enslaving the Earth would be that we have an industrial base already present. The aliens might have better industrial methods but it takes times to set that production up. Humans already have the basics of resource collection, refining, and processing down. If the aliens gave us specifications, we could build quite a bit for them.

### Violence

Many SF stories explore the possibility that "peaceful" aliens evolved from herbivores. They don't have the temperament, tactical thinking, strategic thinking, and sheer knack for destruction of humans. A species looking for warriors could do worse than humans.

In this case the aliens would probably need some mental gymnastics to justify the slavery.

And they'd be shocked by what we do with the alien provided equipment to earn our freedom.

I think a scenario could be:

• They are technologically advanced enough to be immortals (which keeps their population low).
• Humans may be relatively massive compared to the aliens.
• With advanced nanotechnology they could easily engineer viruses that would wipe out humanity, so we decide to bow to them.
• With 7+ billion humans, we could easily move massive amounts of resources to whatever technology they have to bring resources back to home planet.
• Being tiny, their robot technology might as well not be as practical as humans.
• Humans know the planet very well and have infrastructure in place to gather the resources. We would be very adept at extracting it.

The aliens can't use machinery on the target planet to perform manual labor because there is some sort of electromagnetic field or w/e that makes machinery operation there impossible (not their home planet, but a third planet that they've discovered). The planet contains resources that have to be mined for warp drive, etc.. The aliens would probably use us for manual labor regardless; but on their own world, gravity is so low that their musculoskeletal systems are much weaker than ours (similar to the classical stereotype of extraterrestrial physiques), and they make rampant use of machinery for physical tasks.

We make great pets.

We can open bottles of beer with our hands, teeth, and eye sockets, among other things.

We can be fun to watch.

We understand our environment, how to nurture it, and how to destroy it.

Some of us would be amenable to slavery, or at least lives of servitude.

We think that interstellar travel will be hugely expensive, but we say this as a species who has never done it and doesn't know the ways in which it might be done. Recently scientists thought they might have created a warp bubble in an experiment, causing lasers to move faster than the speed of light. It turned out to be a mistaken calculation and not a warp bubble at all, but maybe creating warp technology is way easier than we think it is.

If this species' form of interstellar travel is relatively cheap, there are any number of reasons they might have discovered it before automation. If our recent experiment had turned out to be a real warp effect, we might be developing warp technology even now, before replacing miners and slavery on our home planet. The aliens might not be very technologically advanced at all, if they stumbled onto warp technology earlier in their timeline than we did. Maybe something in their psychology makes them more able to understand warp tech than automation, or more likely to invest their resources into that area of R&D. Maybe they're just so physically awesome and up for most tasks that they never really bothered even coming up with an idea like automation, but there's some reason they can't do this particular job well (or it's just too risky) and need humans to do it.

The planet might be somehow corrosive to mechanisms but not to humans. Even just sand storms that they can't adequately keep out of their gears, and they don't care if it gets into humans' "gears." Or they can heal our sandblasted eyes cheaper than repairing a machine, and those savings will eventually outweigh the cost of getting the initial stock of humans and then breeding us. Depending on how expensive interstellar travel is, humans might be cheap labor or an expensive and risky investment that the mining CEO will protect at all costs.

If the alien race is at all bureaucratic, there might be some kind of subsidy or loophole where a mining company has access to interstellar travel but not automation, and this entrepreneur owns a backwater planet and this is how he decides to harvest it and make himself wealthy. If it's a long-lived species, the slavers might be content to wait centuries before the human slave experiment returns on the initial interstellar investment.

Or even an alien kid borrowing his dad's interstellar car. The rest of the civilization might be enormously advanced but this person doesn't have to be.

Zecharia Sitchin in his ancient astronaut theory had aliens with relatively low tech compared to most sci fi aliens. They happen to live within our own solar system, on a planet with a strange orbit that's far beyond Pluto much of the time, so they didn't need FTL or relativistic speeds to get to us at all.

If the aliens are a parasetic race that are capable of using mammalian hosts. They will take the humans as another species of host to add to their ever-growing collection.

Perhaps it even pleases this species to try out different hosts, perhaps they use other species as we use shirts and shoes - to protect from the elements and as a fashion statement.

• Alien A - "Greetings brother, what species do you wear today?"
• Alien B - "Why, it is a new species the research teams found in a distant galaxy. An ugly sort, but what wonderous dexterity they have. Behold, I can grip this alien writing implement with ease!"
• Alien A - "Truly amazing. Much better than this three-fingered reptile I am inhabiting."

Because aliens have a different perception and culture, what to they is freedom to us is slavery and viceversa. Actually the concept of freedom varies greatly even among humans so I would not be surprised it is the same between humans and aliens.

Maybe aliens' life is so evoluted that they disregard someone doing nothing, and enforce Others to do their best to achieve their "true" potential.

I would not be surprised if aliens creates a series of competitions on a very wide set of skills (going from olimpic-like games to art competitions etc, even meal cooking competitions). Basically for every small aspect of our life aliens are going to force a improvement schedule based on prize/punishment system (food in Exchange for achievements, electrocution in case of failure).

Also they would organize the society so that it becomes sustainable without economy, but forcing everyone achieve its true potential while producing the minimal necessary for Others (food, services all would become in 2nd place).

Something like:

• 7 am, harvest crops
• 9 am shower
• 10 am start hand-waving improvment excercises.
• 22 pm hand-waving competition
• 0 am go to sleep.

Basically they would force ourselves to become gladiators of our lifes.. hei isn't the same thing happening in some TV shows (a part electrocution, well some shows have that too in reality). Maybe TV shows are organized by aliens? P_P

O_O