On 15/06/2016 5:22 am, Brent Meeker wrote:
On 6/14/2016 10:09 AM, Bruno Marchal wrote:
Let me explain shortly. First we start from consciousness, by
(re)defining computationalism as the assumption that there is a level
of description of myself such that my consciousness remains unchanged
through a functional substitution made at that level.
But already at the beginning you have swept the problem under the
rug. Notice that you could replace "consciousness" by "physics" in
the same sentence. You're just assuming that whatever you're talking
about can be computed - which is OK, but it's not solution to the
problem of consciousness until you can say exactly which computations
are conscious an which are not. I think it is interesting that you
consider spiders conscious, but not plants. What's the difference?
Obviously it's the degree and scope of interaction with the
environment. Which to me is further evidence that you implicitly
recognize there can be no sharp division between matter and mind.
I agree with you here, but I think that Bruno has an even more serious
problem: it seems that there is an inherent circularity in the above
computationalist account of consciousness.
The starting assumption is that consciousness is unchanged by a
functional substitution at some level. But what does a "functional
substitution" mean in this context? It is clear that Bruno is thinking
of replacing some or all of the human brain by a functionally identical
machine. Firstly, that assumes supervenience of consciousness on the
brain -- something that is not part of the definition of consciousness.
And secondly, it assumes that a different substrate, one that can
instantiate computations independently of brains and consciousness,
exits. If you are going to substitute something for something else, you
need something else by which to make the substitution. In this case, the
implicit assumption is that we have a physical computer that can be used
to carry out the required computations. But no such physical machines
exist if we start with consciousness in isolation. Bruno wants to deduce
the existence of the physical by some statistics over computations going
through the particular consciousness. But this is viciously circular if
he has to assume the existence of that physical level at the start. He
hasn't derived or deduced it -- he has simply assumed it.
Bruce
--
You received this message because you are subscribed to the Google Groups
"Everything List" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to everything-list+unsubscr...@googlegroups.com.
To post to this group, send email to everything-list@googlegroups.com.
Visit this group at https://groups.google.com/group/everything-list.
For more options, visit https://groups.google.com/d/optout.
