On Tue, Aug 14, 2012 at 11:33:48AM +0200, Bruno Marchal wrote: > > > >"That which exists" is fundamentally unknowable, and probably not > >sensible disucssed, hence I prefer to stick with more neutral labels > >like "syntactic level". > > I disagree with this. With comp we know that the fundamental reality > is given by *any* Turing complete system. What cannot be discussed > is which one, but they are all equivalent. >
I don't think we're in disagreement here. > > > > > >As for being independent of us, both syntactic and semantic levels are > >independent of us in the sense that two correspondents must agree on > >both in order to have a sensible conversation. > > I disagree. Semantics is personal and ill defined, and we don't have > to agree on the semantics to discuss. We have only to agree with the > syntactic provability rule. The whole field of logic is based on > that: the validity of the reasoning are made independent of the > semantics, which is always subjective and personal. > > I am using syntactic layer and semanatic layer as I define them in my book. Observers do need to agree on these to have a sensible conversation about complexity and emergence. I'm not sure if your "semantics" is the same thing at all. > >I'm not sure that a pseudo-random algorithm would always be good > >enough, as unless it is cryptographically strong, evolution will make > >short work of breaking it. If a real random oracle is available, it > >would be some much easier to use that. > > Technically it can be shown, indeed, that random oracle are richer > as a resource for problem solving than pseudo randomness, but the > proof of this are very non constructive, so that it is hard to > conceive any practical problem for which a random oracle is better. > I am not sure I see the relation with cryptography. > Cryptographer require that their key generation routines are utterly unguessable. A cryptographically strong PRNG is one whose sequence is not easily reverse engineered (in I suppose some NP-hard sense). > > > > >If you have a coin, then flipping a coin is a good approach. Most > >brains so not have coins, so I would expect a different mechanism to > >be used - eg synaptic thermal noise. > > But we don't know in Nature any random process, unless you believe > in the collapse of the wave packet. > I believe beta decay is truly random, but only believe in subjective wave function collapse. Beta decay must therefore be a 1p phenomenon. No particular problem there. > > > > > >> > >>Note that NO machine can ever distinguish a truly random sequence > >>with some sequence which can be generated by machine more complex > >>than themselves. > >> > > > >That is true. But complex machines are expensive to run. > > But with comp we don't run machine. They all exists and run in > arithmetic, and the appearances are internal selection. Below the > subst level we are all confronted with an infinity of unbounded > complexity (cf the white rabbits). > > > > >Real random > >oracles, if available, > > They are available by first person indeterminacy. They are not > ontologically real, but they are epistemologically real, and this > plays a big role in the emergence of the physical reality. But I > doubt it plays a role in our biological evolution. That would mean > that our substititution level is lower than the quantum one, and I > don't see any evidence for this. > I don't see that. Evolution will use whatever it can get its hands on. If it has a source of true random numbers on hand, it will use that in preference to evolving a cryptographically strong algorithm. This is for situations where an animal must outsmart another (eg predator, rival from same species, etc). In the case of solving NP-hard problems, randomness is useful, but its harder to see that cryptographic strength is needed. Nevertheless, I suspect that evolution will favour the use of real random oracles rather than evolving PRNG algorithms. >>>>but which is not the non-compatibilist kind of randomness that some > >>>>defender of free-will want to introduce. > >>>> > >>> > >>>I have never met anyone wanting to do this. They sound like > >>>some sort > >>>of long-discredited Cartesian dualist. Are you sure they're not > >>>strawmen > >>>you have conjured up? > >> > >>John Clark seems to believe that they still exist, as he argues all > >>the times against them, and then it seems to me that Craig Weinberg > >>has defended such notion, I think. > >>I don't think I have conjured up :) > >> > > > >John Clark argues against anyone who utters the words "free will". I > >don't think he particularly targets the "spirit free will theorists" > >(as Brent calls them). > > But he agrees and even proposes a compatibilist definition. > I'll let him speak to that, but its not the impression I get. > >No, but it does need 1-randomness > > Imagine the iterated WM-duplication. Why would the resulting peoples > have more free will than the same person not doing the experience? > It seems to me that if a decision relies on a perfect coin, it is > less "free" than if it relies on my partial self-indetermination, > which itself is a deterministic process, although I cannot see it. > Assuming the coin is operating inside the agent's body? Why would that be considered non-free? -- ---------------------------------------------------------------------------- Prof Russell Standish Phone 0425 253119 (mobile) Principal, High Performance Coders Visiting Professor of Mathematics hpco...@hpcoders.com.au University of New South Wales http://www.hpcoders.com.au ---------------------------------------------------------------------------- -- You received this message because you are subscribed to the Google Groups "Everything List" group. To post to this group, send email to everything-list@googlegroups.com. To unsubscribe from this group, send email to everything-list+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/everything-list?hl=en.
