One soul, one body. Every soul has one body, and every body has one soul. How distressingly conventional. What else can we imagine?

One soul for multiple bodies. Think of yourself as a hive-mind. Or a puppet-master, orchestrating multiple humans as they go about their business. Everyone’s a puppet-master, of course, but most of them only control one human while you control several. Or at least, you think.

In the nocturnal wanderings of my mind, you’re a mixed barbershop quartet. You can sing in spontaneous four-part harmony, the soprano, alto, tenor, and bass coördinating perfectly because they’re all you. Your choreography is impeccably precise and in sync with each other, because all four of you are you.

You live together in the house that your four day jobs have paid off. You can cook, clean, fold laundry, and shower at the same time. Very few words are spoken between yourselves, because why would you need to speak to one another? That would be like my left arm trying to send a message to my right leg. You can watch four movies at once. You can even have sex between two (or more) of yourselves, but I guess that would be masturbation.

You can also play terrifying pranks on your guests.

Multiple souls for one body. You share this body with another soul, like roommates. You’re like half of a person. Maybe you control only a subset of body parts. Like, you have autonomy over the left half of the body, and she gets the right half. Maybe some body parts are under dual control. It’s like you and she are both steering the same car.

Or why stop at two? You could have a lot of souls in one body. Maybe you only get the middle toe.

Another possibility here is the Inside Out model. You’re like one of the emotions in Riley’s head. With the other souls you are steering your human around. Maybe there are hundreds of souls and you all compete for some degree of control. Maybe you join factions, political parties which represent blocs of souls in the struggle for the power to determine your human’s actions. It’s like a country.

On the outside, you’re a vaguely dysfunctional human. But then again, countries are like this too, and I assume for much the same reason.

Multiple souls for multiple bodies. Oooh this gets interesting and hard to think about. It’s like you own fractional shares in multiple humans. Maybe Soul 407197 is Deborah’s left leg, two-fifths of Alma’s conscience, Camille (in full), Parth’s T-cells, and Pete Buttigieg’s right nipple.

A more skilful author than I could write a thriller whose protagonist is Soul 407197. I wonder what that would be like.