On 1/19/2014 4:14 AM, Bruno Marchal wrote:

On 18 Jan 2014, at 05:27, LizR wrote:On 18 January 2014 17:16, meekerdb <meeke...@verizon.net <mailto:meeke...@verizon.net>>wrote:On 1/17/2014 5:40 PM, LizR wrote:But apparently the brain has a lot to do with those computations in Platonia, c.f. anesthetic. Notice that I'm not a disciple of Platonia. Me neither, I am agnostic - but within comp it is assumed, so while discussing comp we have to assume it (unless we're rejecting comp on that basis). But I can see that Platonia makes sense in that 17 does seem to be prime idependently of you and me and everyone else, which is (I'm told) enough for the whole shebang to come into some sort of existence.I don't think you have to buy the equivalence between (17 is prime) is true and (17 is prime) exists. In fact Bruno always says you only have to believe the first for his argument to succeed. But then he slips in the UD and it seems that every truthof arithmetic implies and existence. I think this is the same problem as step 8.If everything has to be simulated, then there's no difference between simulated andreal. If I'm "really" existing in an infinity of world/simulations that are *just like this one up to now* - then they ARE this one (c.f. Leibniz).Well, I haven't managed to get my head around step 8, at least, not if step 8 is theMGA? (Or maybe I did, if it isn't....)May be there is a simpler argument than step 8 (MGA). It is the fact that you needmagical (non Turing emulable) matter for a machine being able to distinguish "realmatter" (what could be that?) from its an arithmetical emulation.

`Not if the machine is made of "real matter". I think a machine made of arithmetic can`

`only count numbers as "real matter".`

Brent

So, even without the MGA, you can understand that the notion of "real matter" can onlybe a reification of an unknown (real matter) to prevent the use of a simple theory. Thismakes already the "real matter argument" like a creationist god-of-the-gap.MGA just extends this in showing that not only that "real matter" is a reification, butthat it needs some quite ad hoc components. Not all philosophers are againstreification, so MGA makes the absurdity of doing that reification (in this context) muchmore palpable.I suppose what I need to know is how the existence (in any sense) of the integers andelementary arithmetic operations creates computations.Yes, that is a key point. It is not simple to explain, although more or less standard inmathematical logic.The problem here is that we must distinguish between a computation and a description ofa computation, and understand that if RA can prove the existence of a computation onlythrough the existence of a description of a computation, then the computation exists.This is subtle because it needs to see well the difference between syntaxical sentencesand semantical statements, ...We can come back on this. It is well done in some books.In fact every possible computation. I believe it's done indexically, whatever thatmeans ... but I think this is about where I start to feel I shouldn't bother my prettylittle head.If the sheer existence of numbers, + and x implies that all possible computations"exist "(in an abstract sense) then it all follows - in an abstract sense.Yes, and the concrete experience will exist too, in that abstract sense, and that's isenough for the existence of indexically concrete experience. Tegmark is right on this(but not original in the prior publication sense).This brings me back to your comment about equivalence (or not). The thing is, I'd liketo know what I'm buying or not buying before I decide whether to buy it!You need to buy only two things: "yes doctor" and Church thesis. AR is implicit inChurch thesis (and in the whole of science, I would add).Bruno--You received this message because you are subscribed to the Google Groups "EverythingList" group.To unsubscribe from this group and stop receiving emails from it, send an email toeverything-list+unsubscr...@googlegroups.com<mailto:everything-list+unsubscr...@googlegroups.com>.To post to this group, send email to everything-list@googlegroups.com<mailto:everything-list@googlegroups.com>.Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.http://iridia.ulb.ac.be/~marchal/ <http://iridia.ulb.ac.be/%7Emarchal/> --You received this message because you are subscribed to the Google Groups "EverythingList" group.To unsubscribe from this group and stop receiving emails from it, send an email toeverything-list+unsubscr...@googlegroups.com.To post to this group, send email to everything-list@googlegroups.com. Visit this group at http://groups.google.com/group/everything-list. For more options, visit https://groups.google.com/groups/opt_out.

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