Suppose that we decide on a taxonomy that separates the mind and body. Over here, the mind. Over there, the body.
This creates the subjectivity hole of "but we only ever experience the mind, so what is the body? What is the reality the body lives in? How can we say anything about these things?"
Suppose we build a bridge between these things by saying "oh, here's the trick: mental models become arbitrarily close to reality as fidelity goes to infinity."
(This is a common bridge that people build. It's behind everything from the ontological argument for God to "are we in a simulation?" It's pretty easy to see why people would land on this bridge in the modern world a lot, given the impact and effectiveness of the scientific method.)
Then, having decided this taxonomy, and built this bridge, the question of free will becomes pressing. If our mental models of our own mind, and others', become arbitrarily close to reality as fidelity goes to infinity ... how to humanize them, and ourselves, becomes both pressing and unclear. Do we build these models as deterministic things---sequences, or computer programs; put another way, numbers? Do we try to dodge the implications or mitigate the imperfection of our models by introducing randomness? If we understand the world in terms of replicable experiments with a statistical spread of outcomes, are we the deterministic constructs of the paper writing these things up, specific words in specific order, front to back, and ended, or the random results of individual experiments?
I grew up in this world. I find the base ideas here compelling. I loved the idea that everything was just a Gödel number as a kid. I spent way too many hours interrogating the ontological argument. But also there's something pretty wack in this line of thinking:
Existence and experience are the only things we even approach knowing to be real, so we probably shouldn't optimize them out of the equation.