How is it a reasonable belief that a highly complex entity beyond our comprehension is a deterministic machine? Aren't deterministic machines simply the limit of our knowledge for now?
Except the human mind isn't at all just "software". If the human brain is deterministic, nothing is not.
The human brain doesn't have "a lot of" inputs, but rather infinite inputs. Cosmic rays, (self-emitted) electromagnetic fields, bacterial/viral activity, nutrition, genetics, epigenetics, immunity, cellular function ... all these things effect a mind. There is homeostasis, but that's not like error correction in silicon computation. Neurons do have excitation thresholds which are somewhat digital, but they are embedded in analog signaling and interference.
Row-hammer-like interference is a normal state of affairs for the brain. You cannot core-dump a mind. Measurements will change its state since it's inherently linked to the state of its matter. You could halt an LLM and predict its state the next cycle going by the program's logic. Or you could halt it, copy the state and get two identical instances. To clone a brain, you likely need to halt time itself.
Semantics aside, there is clearly a different deterministicness.
> The human brain doesn't have "a lot of" inputs, but rather infinite inputs.
That's not true though. It's 'a lot', not infinite. Not everything affects the output that our brain produces.
As far as we're currently aware the brain IS deterministic. If you were able to perfectly duplicate a brain and it's environment/state, the resulting output of that brain will always be the same.
> Not everything affects the output that our brain produces.
It responds to EM fields...so yeah, basically infinite.
> If you were able to perfectly duplicate a brain and it's environment/state
Big if. As I said, if the brain is deterministic, everything is. And then it's a meaningless discriminator. I already explained why I think you can't duplicate the state/environment perfectly.