On 25 Jan 2011, at 15:47, Stephen Paul King wrote:

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The supervenience thesis is separate from the Turing thesis andMauldin does a good job in distinguishing them.

`Just to be clear, what Maudlin call "supervenience thesis" is what I`

`called "physical supervenience thesis", to distinguish it from the`

`computationalist supervenience thesis.`

`The computationalist supervenience thesis is basically what remains`

`when we keep comp, and understand that the Phys. Sup. thesis has to go`

`away in the comp frame.`

The problem that I see is in the properties of physicality that areassumed in Mauldin’s argument. It is one thing to not be dependenton what particular physical structure a computation can be run on(assuming a realistic supervenience), it is another thing entirelyto say that a Turing machine can be “run” without the existence ofany physical hardware at all.

`Well, in the branch ~MEC v ~MAT, Maudlin seems to prefer MAT, so he`

`seems with you on this, I think.`

I am trying to make this distinction and trying to fix this problemthat I found in the supervenience thesis within Mauldin’s argument.He does point out that there are contrafactuals that must have somephysical instantiation. We see this on page 411 where he wrote:“The only physical requirement that a system must met in order toinstantiate a certain machine table are that (1) there must be atleast as many physically distinguishable states of the system asthere are machine states in the table, (2) the system must becapable of reacting to and changing the state of the tape, and (3)there must be enough physical structure to support the subjunctiveconnections specified in the table.”It is in the subjunctive connections that we see thecontrafactuals expressed. If one’s model of physical reality doesnot allow for the necessary subjunctive connections to beimplemented then the supervenience thesis would fail independent ofthe Turing thesis.

OK.

My point is that we need to be careful about what exactly do we meanby “causally inactive piece of matter”. If there is material presentwithin a physical system that does not affect the 3 requirementsabove then surely we can agree with Mauldin’s claim, but if there isa problem with the faithfulness of the model of what physicalityinvolves, then this must be fixed if possible. This is why I saythat there is a bit of a straw man in his argument.

`Maudlin should have said: "causally inactive piece of matter`

`*relevant* for the computation. This is what I did, and it makes the`

`argument independent of the counterfactual re-instantiation. The movie-`

`graph is simpler with that respect. But this can lead to some`

`ambiguity too.`

Mathematical structures do not “do” anything, they merely exist,if at all! We can use verbs to describe relations between nouns butthat does not change the fact that nouns are nouns and not verbs.The movie graph is a neat trick in that is abstracts out the activeprocess of organizing the information content of the individualframes and the order of their placement in the graph, but that someprocess had to be involved to perform the computation of the contentand ordering cannot be removed, it is only pushed out of the fieldof view. This is why I argue that we cannot ignore the computationalcomplexity problem that exist in any situation where we areconsidering a optimal configuration that is somehow selected fromsome set or ensemble.

`I don't see how this would change anything in the argument, unless you`

`presuppose consciousness is not locally Turing emulable, to start with.`

Another question that I am asking is what relation doesinformation have with matter. We had a paper that seems to proposethat information is physical and then goes on to make some strangeclaims.

`OK. And the problem with the word physical is that it means different`

`things in different settings. The main confusion is between`

`fundamentally physical, or material, with a conception of primary`

`matter, or it means "related to this or that physical theory" based on`

`abstract mathematical relations.`

We also had a recent paper that discusses how “information isconverted into free energy” by a Maxwell Demon-type feedback system.It seems to me that there is a lot of confusion about whatrelationship there is between information and matter, so myinquisitiveness could be seen as an attempt to make sense of thismess.

`And the word "matter" is similarly ambiguous, and never defined,`

`except by Aristotle which provides the "& Dp" idea, implicitly used by`

`the Platonist Plotinus to define matter in the way used by the self-`

`observing machine.`

`Matter is what is indeterminate, and oppose to intelligibility (Bp).`

`It is of the type ~Bp, that is D#. This is coherent with the idea that`

`a physics is, before all thing, a probability or plausibility`

`calculus. Cf also Timaeus (Plato) bastard calculus, and the Kripke`

`semantics of "Dp" in modal logics: Dp = it exists a world satisfying p.`

One idea that could be proposed is that information is arelationship in a triple such that a difference exists between twothat makes a difference for the third. I am sure that this can beput into more formal terms. Turing Machines aside, we are not reallygetting to the problem until we have a good set of tools with whichto examine the question of how to determine the substitution levelof a given system and even if substitution is possible.

Here I disagree 100%.

`It is proved that if we are machine, then we cannot define and prove`

`what is our substitution level. No machine can ever know which machine`

`she is. This is what I have called the Benacerraf principle in older`

`post (and my theses).`

`For any machine defined as such in a 3-way, the substitution level is`

`built in the plan of the machine, by definition.`

We can play with theoretical concepts and toy models all of ourlives, but if and until they have concrete physical realizationsthey are mere figments of our imaginations.

`I disagree again. We can use them as theoretical tools. Most of`

`theoretical computer science is not constructive, and most of the`

`times necessarily and provably so. That is another reason why it is`

`closer to theology than to engineering.`

Bruno

`PS I know you are dyslexic, so I just tell you that the "L" in`

`MAUDLIN, is after the "D", not before.`

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