Even if you are a full materialist it's fallacious to assume there is one "part" that does something, like it's a factory assembly. Instead it might be a function of the composition of brain parts.
It's like asking which part of a bat makes it fly. The wings? Well kind of, but you need more than that. I guess you can fly without feet... it's just not a well formed question.
If you ask question a bit differently, then it's not a mystery at all. Why brain parts that have neural structure, which is conductive to fine and agile motor control, perform motor control?
> Even if you are a full materialist it's fallacious to assume there is one "part" that does something, like it's a factory assembly. Instead it might be a function of the composition of brain parts.
Its true that a particular function may mot be localizable more specifically than the brain (or even the whole body), because defining it as a distinct function may not reflect the organization of conponents within the body. But that's still performed by a defined physical system, and there are still sub-functions necessary to perform that function that are localizable to narrower components.
> It's like asking which part of a bat makes it fly.
Its like that in that we absolutely can describe specific parts of the bat and what each contributes to flight.
It's like asking which part of a bat makes it fly. The wings? Well kind of, but you need more than that. I guess you can fly without feet... it's just not a well formed question.