The inhabitants of this world are human shaped but all components of their bodies are independently sentient. Each person is effectively a civilization unto themselves. There are mages and healers. They levitate everywhere - their mating ritual is an annual get-together where they simply stand up against each other and let their parts do what they do, then the woman buries it underground. The fetus gestates by absorbing nutrients from the ground and weaving magic into clothing. Either the various 'tribes' of the person cooperate and levitate out of the ground when they come of age, or they never do. But in general, apart from this annual(?) mating ritual, everyone avoids each other.
The clothes are consumed when they cast spells so they have other spells to weave new clothes. They don't really care about sex or the weather so people frequently shift from naked to fully clothed and back over the course of days or even hours.
A human ends up here and the first thing they usually say when they see the human is "how did you agree to stay on the ground?" It takes an effort to speak because the various parts of the body have to agree to it first and it's rare for them to agree on something - even in a crisis when they all agree something must be done there is disagreement on what. But there is no circumstance where a mage's feet would agree to carry the weight of the whole body. The mages come to consider the human as someone who has subjugated his body to the status of a beast of burden, therefore.
'magic' is due to picobots in the air - there are about as many of them as there are oxygen molecules on the planet, indeed they latch on to it. But they were designed with whole-body sentience in mind. The best they can do for our character is allow him to breathe the shift in the atmosphere towards substantially less oxygen and, of course, translate. These picobots also act as a partial brain which gives every cell of the human body the processing space it needs to achieve its sentience. It took some evolving to adapt to it, however, which is why our main character can't really access it. However, the picobots might be able to provide some limited version of that functionality.
Perhaps an inevitable duel between the human and a mage occurs during this annual mating ritual. The mage only barely achieved a majority agreement to even have the duel so of course it took several seconds to agree on which spell to cast. More than enough time for the human to simply walk up and punch the mage in the face. It wasn't a particularly hard punch - if the human was punched so, despite having never been in a fight before, he would have been able to brush it off within two minutes. But it was the hardest punch in this world. The mage's civilization goes into crisis mode but of course they still can't agree on what to do about it. The human drags him to the ground. The mage's back protests and demands the top priority be to have someone else bear the weight. The face demands the top priority be to cast a spell to incinerate the human. The feet insist that if someone is to bear the weight it shouldn't be them since they didn't agree to this duel. The hands that cast spells resolve to stay out of it until a simple majority consensus is reached as they also didn't agree to this duel. The rest of the mage argues aggressively for both sides.
It doesn't really matter, though. Despite all of this the mage does pull it together and then beats our protagonist easily. They then send him underground where he meets an underground civilization.
However, the beginning of the story sees the human run in to a healer. The healers and mages are kind of antagonistic to each other. Almost enemies. But while the mages can attack healers from a safe distance pretty much indefinitely, the healers can heal that damage indefinitely, too. However, the healers can't do anything back, so it's kind of a constant standoff except during mating day. The human teaches the healers how agreeing to stand for the consensus even when you disagree with it can help. The healers all have something like this going on within their bodies but never considered grouping up as healers to fight back the mages.
He comes upon a woman burying something.
[some introductory speech]
"Ah, my daughter's time freeze cast. Random shit comes out of it. For most of eternity earth has been a lifeless rock so that's what usually comes out. But every once in a while we get something else. This is the first time a person came out."
[why are you burying a child]
When they rise out of the ground we call that undergoing an emergence.
How long does it usually take for them to emerge?
No, undergo an emergence. They don't emerge.
They come out of the ground.
Well yes.
They emerge from the ground.
That's only on the surface. Their consciousnesses have all decided to work together instead of dissolve and decay into chaos. That's emergence.
Huh?
You are lucky as we just graduated a child and so explaining things to those of completely foreign minds is fresh in our minds.
After, it is decided he is a mortal - the mages are immortal. Once buried, if a child doesn't undergo an emergence they sink into a subterranean underclass. Demons, of sorts. The surface class at some point learned to undergo an emergence they have to purge themselves of the cells that have ideas about purging others. The underclass finds this paradox unacceptable and so those cells that purge others eventually takes over completely, effectively holding the others its mind as servants. It gives them hypothetical problems and they each slavishly think of a solution independent from each other. The demons pick the best solution and keeps a tally of which cells are most useful. Eventually another subset of cells pick the best solution instead of the demon. The demon thus is never burdened with making any decisions and refuses to ever be responsible for the outcome of its actions, instead attributing all mistakes to the legion of cells who do all of its decision making. The demons have purged themselves of every possibility of feeling a negative emotion and so take a particular pleasure in telepathically watching others feel it. They have developed extreme empathy for this purpose with the picobots - which are here too and they still try to help in their way but because of the hierarchy within each person the picobots are limited. Our time traveler is an exception of sorts - because his cells aren't sentient he has far better command over them. He is told that humanity did all of this to itself to pursue immortality and while the mortals do die eventually they live a long time before that. But it is mostly a sort of torture to live this way until one has successfully purged every single chance at a negative emotion - as the final cell is always regret for purging all the others. The traveler asks why don't they just come to an agreement and do the emergence and is met with scoffs and excuses but not the paradox of tolerance.
The cells get their sentience from past souls. The afterlife is basically the same thing as life but in an added dimension and the universe in that extra dimension is less evolved than ours. Souls are like bits of sand in primordial earth still trying to coalesce into something that can cooperate and compete in a way that allows them to use the fourth dimension. They are all just kind of mashed together across the surface of that but still an infinitesimal distance from the surface of our own. The mage race learned to harvest all these 'flat souls' that were just lying around and put them into the sentient components of their bodies.
The mages exist because humanity once tried to become immortal and found the way to do so was to just create a civilization within them so that all of the things that made a civilization immortal can now grant that to a person. The life cycle of cells and their own cultural rules help weed out the most barbaric of other cells which assures a continuous selective breeding process. This, of course, is considered racism within the cells which is how it is revealed that the desire to impose selective breeding is itself a barbaric ended up being the key trait that needs to be selectively breeded out (i.e. purged) in order to produce a sustainable immortality. This is how they discover a culture can only survive if it is built on a fundamental hypocrisy. No one can survive on truth: exclusion of all who disagree with our ideal to be inclusive, a persecution complex among those who believe themselves rugged alpha males, internal division among those who pretend to consider the whole worthy of exceptionalism... In order for a culture to exist that contains the diversity of responses to failure necessary to patch together a definition of - and path towards - absolute success, it must be completely free of selective breeders, which it accomplishes by selectively breeding out the selective breeders.
The training necessarily can not state directly to selectively breed so survival depends entirely on the ability to figure out for oneself that they have to be a hypocrite to survive and that everyone else does it too but for the sake of survival absolutely no one talks about it. So a lot of children sunk into the underground civilization. But the bots extend underground, too. And they are meant to be the servants of humanity so they do still try.
