> So, it seems to me a reasonable starting assumption that intelligence is a result of the mechanistic universe. > Do we have any evidence for something outside the physical, mechanistic universe impacting human cognition?

Problem is, even granted the above, that's not enough of an argument that AGI is only a matter of mechanism.

Take the analogy with pain. We've discovered the mechanism for pain. That it's e.g. some stimulus applied to skin which sets of nerve signals that register in the brain. To then say that the experience of pain is the same as the physical mechanism we've discovered still misses a key step:

what does the experience of pain inhere to, and is that the same subject as that for the mechanism of pain?

Comparing AGI and human intelligence has the same problem. We don't know exactly what is intelligent in either case, let alone whether the two are comparable. So it's not a question of intelligence per se, but of that which is intelligent. Maybe AGI, the way we are thinking and talking about it, is unavoidably tangled with having to grapple with [self-]consciousness.