> Does this analogy hold?: Someone suggests a computer's operating
> system
> is responsible for controlling which program runs on the CPU at any
> given
> time. Someone else says, no, it is a combination of the operating
> system
> and the hardware. True, the hardware is a definite factor, but
> irrelevant
> to this level of description.
>
Typical computer hardware is a Universal Turing Machine:
it can do any info processing task for which a program
can be written. Brains are not like that. They are much,
much more capable of some kinds of tasks than others,
and there are probably some tasks of which they are
absolutely incapable. So hardware is not irrelevant.
Adequate descriptions and explanations of what *does* go
on at higher levels can be given without reference to it (I
think) but it comes in when we try to explain why certain
kinds of higher level phenomena *don't* happen in brains.
Certainly, in quantitative terms, hardware considerations
can explain why some kinds of task can be done very
much more efficiently than others.
Having said which, this stuff deserves more thought than
I've given it so far -- this is not meant to be the last word!
But this is, for now:
Robin