[ExI] Modal Realism and Leibniz: (was The Many Dimensional Sculpture)

[Bryan Bishop]

On Saturday 15 March 2008, Lee Corbin wrote:
> Bryan writes in
>
> ----- Original Message -----
> From: "Bryan Bishop" <kanzure at gmail.com>
> Sent: Tuesday, March 11, 2008 8:22 AM
>
> > I would not have expected an implicit connection between MWI and
> > modal realism per Rafal's message. However, I took this opportunity
> > to go look at the Wikipedia article
> > http://en.wikipedia.org/wiki/Modal_realism
> >
> > and I see what you mean:
> >> Modal realism is the view, notably propounded by David Lewis, that
> >> possible worlds are as real as the actual world. It is based on
> >> the following notions: that possible worlds exist; possible worlds
> >> are not different in kind to the actual world; possible worlds are
> >> irreducible entities; the term "actual" in "actual world" is
> >> indexical.
>
> As is so often the case---Singularity Be Praised---Wikipedia rises
> to the challenge brilliantly:
> http://en.wikipedia.org/wiki/Possible_world
>
>     Comparison with the many-worlds interpretation
>
>     The concept of possible worlds has sometimes been compared with
> the many-worlds interpretation of quantum mechanics; indeed, they are
> sometimes erroneously conflated. The many-worlds interpretation is an
> attempt to provide an interpretation of nondeterministic processes
> (such as measurement) without positing the so-called collapse of the
> wavefunction, while the possible-worlds theory is an attempt to
> provide an interpretation (in the sense of a more or less formal
> semantics) for modal claims. In the many-worlds interpretation of
> quantum mechanics, the collapse of the wavefunction is interpreted by
> introducing a quantum superposition of states of a possibly infinite
> number of identical "parallel universes", all of which exist
> "actually", according to some proponents. The many-worlds
> interpretation is silent on those questions of modality that
> possible-world theories address.
>
>     Major differences between the two notions, aside from their
> origins and purposes, include:
>
>         * The states of quantum-theoretical worlds are entangled
> quantum mechanically while entanglement for possible worlds may be
> meaningless;
>
>         * according to a widely held orthodoxy among philosophers,
> there are possible worlds that are logically but not physically
> possible, but quantum-theoretical worlds are all physically possible.

This part (direct last paragraph) needs to be double-checked. I know 
that what Wikipedia writes is mostly true in this sociohistorical 
context, but I also know that if it is not physically possible, then it 
is not 'logic', in the sense of the logic of the physics of the 
universe, you see (coherency, in the same sense that Jef uses the 
word). 

>     Given that both possible-world theories and quantum many-world
> theories are philosophically contentious, it is not surprising that
> the precise relations between the two are also contentious.
>
> So my guess wasn't too far off!
>
> > Hrm. I really would like to add some Leibniz in on this. How could
> > possibilities be as real as actualities? Let me reform my question.
> > Is he saying that possibilities exist in the sense of mental
> > constructs, such that one's lack of knowledge of the world
> > essentially makes the world both the 'real' and the 'possible' as
> > you recursively explore it and make your own representation?
>
> Alas, I'm no expert on Leibniz. Alas, I'm no beginning student of
> Leibniz.  Alas, I hardly rate even as a complete ignoramus on
> Liebniz's philosophical views.  But I'd be all ears for what you or
> others have to say.

No, you -- (see below)

> > A vague, fuzzy set of what the world may or may not be, allowing
> > subjective agents to explore it without messing up too much. Or is
> > he saying that, metaphysically, the possibilities are as real as
> > anything else?
>
> Help. Anyone familiar with Leibniz at all on this score?

No, this isn't about Leibniz. I was asking of Lewis. :)

> > Charles S. Peirce would have something to say about this use of
> > the word 'possibility' since, naturally, it is more tied to the
> > human mind, and he really, really disliked anybody saying something
> > was 'possible' when they did not have the true source code to the
> > universe to figure out the likelihood of something occurring or
> > whether or not something was truly valid given whatever underlying
> > laws of the universe there exist (whether a cellular automata rule
> > or not, just so I can get in my mention of Wolfram and von Neumann
> > etc.).
>
> So what---Peirce wanted to do to "possible" what I want to do to
> "qualia"? That is, prescribe enough laws forbidding its use so that
> the user to can be successfully prosecuted, and probably suffer
> sanctions, fines, and solitary confinement somewhere?

More directly: if it is not possible, then your coherency needs to be 
updated with some new nugget. You would not prescribe laws, but rather 
change your approach by reformulating what you know. Scientists 
probably have to do this all the time (unless they planned to 
avoid 'black swans', in which case they were probably more like 
engineers). 

> > Is Lewis saying that possibilities exist (in the sense that a
> > mental agent can rationalize that something might be 'possible'
> > given his limited understanding of the greater world), or that if
> > we allow such 'possibilities' we automatically must acknowledge
> > their full and total existence?
>
> As you saw, Rafal answered
>
> > ### The way I see it, everything exists. I mean it in the hardcore
> > metaphysical sense - whatever it means to "be", everything you
> > can think of and a lot more, have this property. Even
> > contradictions, even inconsistent logic, even mathematical
> > impossibilities exist, as hard [real] as rocks, except we are not
> > there to touch them.
>
> and that seems like maybe what Lewis was saying indeed.

I see. How can you mean it in the "hardcore metaphysical" sense, anyway? 
Hardcore means hardcore: cold, hard reality. Ah, well, I suppose we can 
step it up to a meta-level, but I don't think this is what Rafal _or_ 
Lewis means. By my meta-level, I mean in the sense of Egan, in the 
sense of his line: think about it; even if you are constructing the 
most ridiculously arbitrary mathematics in existence that has no 
relevance, you've just made it relevant to yourself! And so even 
inconsistent logic can be mapped back to our brains, and there is no 
law in reality saying that our brains can't have the chance to 'mess 
up' and make inconsistencies and incoherencies. But I think 
Rafal's "hardcore metaphysical" is more like Platonic Idealism -- 
a "meta dimension", which I can't (by the (un)nature of the thing 
itself) pin down. I recommend we apply So-And-So's rule here: we keep 
discussion to what we can access in reality and do, etc. etc. I do not 
know the actual name of this rule, I am pretty sure it has existed 
before.

> > I like to use Leibniz's optimism and his definitions from time to
> > time: 1) real - necessarily existent
> > 2) impossible - necessarily nonexistent
> > 3) possible - unnecessarily nonexistent
> > And a few others. I realize now that I cannot recall a link that
> > explains this terminology, but I do think it is still useful here
> > since it ties possibilities/reality/actuality back to terms re:
> > necessity and coherency.
>
> Thanks.  Sounds useful to remember this about the views of the great
> Hannover genius.

I was offering it up for grabs, in the sense of taking it and using 
those vocabularies in this discussion. ;)

> > If anything it should be more like an observer bias to calculate
> > out [overcome?] due to the anthropic principles and so on, since
> > all subjective agents would present a slightly different bias in
> > consciousness or awareness;
>
> A classic example of a sentence needed a follow-up or two:  "That is,
> ...", and "In other words....".  I'm having trouble parsing that.

That's because I am having trouble processing the thought in general. I 
can explain it from a completely different perspective that I have come 
across before (on my own), but this is by no means helpful in expanding 
the concept, perhaps only in letting it incubate in a few minds. From 
time to time over the past decade, I have taken to the 'metaphysics' or 
whatever of existence and the Beginning question: i.e., how could 
something come from nothing? How could there ever have been nothing, 
since nothing is something, but that something was nothing, which was, 
and on and on and on. More recently I have formalized this as taking 
Occam's razor to any idea, to any question, and chopping down at it. I 
ask you to take the razor to any concept that you can think of, and use 
the razor (go on, do it -- cut away). No matter how much you cut, you 
still have something left. This seems to be the same with the anthropic 
principle and my personal perspective on reality, naturally since the 
knife cannot cut itself. So, Tegmark apparently argues that this means 
that there are SASes all the way down to the fundamental basis of 
reality, but I don't see how he makes that leap, and I don't see it as 
necessary.

> > in more hard sci-fi terms, I'd argue that consciousness may not
> > even exist, despite my experience and my mind, it's not a magical
> > sauce. :)
>
> Well, now that I've come out of the closet about some GLUTs being
> zombies, I could start with the incendiary remark that consciousness
> is the chief characteristic separating zombies from other passers of
> Turing Tests, e.g., us, and other passers for what we ordinarily
> think of as conscious entities (e.g. crows, parrots, chimps, dogs,
> liberals, etc.)

Huh? Turing Test requires another subjective agent to judge some other 
process, it does nothing to do any fundamental provision to ... I do 
not know how to explain this. But the Turing Test doesn't really add 
anything to my toolbox personally, it just adds it to the *social* 
toolbox. I need better terminology (and, to take your requests for 
examples and explanations to heart:). in this sense, the Turing Test is 
a mental tool that is on top of social layers in society, from brain to 
brain, and is generally a result of the various Minskyian filters in 
the brain or other selective processes of attention. Then, somehow, 
a 'decision' is made to press a button, saying yes/no as to whether the 
thing passes the Turing Test. I suppose you could say that I am 
claiming that the Turing Test is not standardized, **but** equivalently 
if we had a 'standardized test' in the same form as the SAT or TAKS 
(the local state-wide "pass to graduate, or else" test) since those 
tests may be 'standardized' but they are not a proof or theorem or test 
in the same sense as we can use a number line test in calculus or the 
various theorem-solvers that are all across the internet.

> >> > Like a GLUT (Giant Look-Up Table) of you? And this is the only
> >> > you, the one and unique representation and the time/place of
> >> > your consciousness?
>
> Oh no.  A particular GLUT in my original usage re consciousness
> focused on a strictly limited period in an entity's life. In other
> words, take an amount of time necessary to administer a Turing Test
> (or any other test you have in mind of finite duration), and create a
> GLUT that would answer just the same no matter what you ask
> the testees, human or GLUT. Sorry if I didn't make that clear.
>
> But now you're proposing a GLUT to characterize a person's
> whole life, and for me, that doesn't work at all, because a person
> (to me) travels through a trajectory in the space of all possible
> people (subspace of all possible algorithms). I hope it's not
> necessary to extend the already mind-bending notion of a GLUT
> that can successfully pass a limited interrogation.

I also thought of a process/tree-thing that would also be 
algorithmically going through such structs and mathematics, yes. You 
should also go see my email when I replied to Rafal after he replied to 
that same comment of mine -- "I was not expecting that diversion" is 
particularly relevant here, as copied below:

> I was not expecting this diversion. Given the distinctions I made
> above, if we discuss them some more, and it turns out that Lewis and 
> his modal realism is more about subjective agents and their GLUTs, 
> rathe than a metaphysical ensemble, then I think that you would have 
> to drop your MWI tie-ins. On my first passing of Rafal's email, it 
> seemed to me that the ensemble that he was describing was merely 
> explanatory, and not necessitating MWI or even itself -- merely as a 
> way to describe data structs in the world that we experience on a more 
> abstract level.        

To continue:

> > [Lee wrote]
> >
> >> Of course, as you know, this is at extreme variance with our
> >> normal usages of the words "you" and the time/places of your
> >> consciousness. For example, either under modal realism or the
> >> MWI, something extremely similar to me (under the conventional
> >> meanings of words) actually received a phone call a few minutes
> >> ago, and so is not typing this. It's a "possible world" under
> >> modal realism, and equally real under the MWI. Below, you use
> >> "versions of you" to talk about, for example, those Rafals who
> >> get to live forever, or those Lees who got a phone call.
> >
> > I was not expecting this diversion. Given the distinctions I made
> > above, if we discuss them some more, and it turns out that Lewis
> > and his modal realism is more about subjective agents and their
> > GLUTs,
>
> Yikes! as said, I recoil from any but a very limited very
> *particular* GLUT covering, for example, a particular testing
> situation. I wouldn't even know where to start to make a GLUT for
> Rafal's Tree or my platonic fuzzy sphere of what a person is in
> configuration space.

Alright, looks like you saw that already.

> > rather than a metaphysical ensemble, then I think that you would
> > have to drop your MWI tie-ins.
>
> Wikipedia's two asterisk's items above already limit the connection
> between modal realism, and the MWI.  It's not clear to me that you
> are adding to the criticism, but maybe so.

Yep, I think I am. See my points about "logic" and if it's logical, then 
how is it impossible, you didn't account for whatever new nuggets in 
reality that you found etc. etc. Simple reasoning ("x causes y") can be 
confirmed in the mind itself, but also in experimental checking (sort 
of), so as you get more advanced, it requires more checking, and I 
think this is why there's that gap where people assume "logic has to be 
so, so there has to be a further reality where this holds" - when in 
fact, the logic is supposed to be confirmed and molded (humbled?) by 
reality, no?

> > [Lee asked Rafal]
> >
> >> Now on your usage of words, you and I and all the Lee's who
> >> were/are fighting in the Second World War, are simply a part
> >> of the great Tree of Me. An immediate difficulty you might want
> >> to address is, "Does the tree of Lee overlap with the tree of
> >> Rafal?"  If not, why not?  My own "fuzzy spheres" do allow
> >> for overlap at their extreme edges.
> >
> > Are not all things, somehow related, if not physically then at
> > least in our minds?
>
> Come again?  How is the most southern orange on the most southern
> orange tree in Florida related to President McKinley's assassin?
> I'm surely the first person in history to inquire about that
> ridiculous "relationship".

And thus you have given ... ah, wait, I have already explained myself 
(as you quote directly below - thanks):

> > Somebody might reply to this saying "try to find a
> > correlation between X and Y" and that would only serve to show that
> > somebody has in fact made that correlation, and the more that
> > people read that email, the more 'real' it is becoming (I do not
> > mean to say that popular approval increases the realness, merely
> > that the content is diffused over the surface area of the local
> > reality, so it is becoming more than the 'nothing' that the
> > original emailer was hoping to select for).
>
> Then the relationship between the Holy Trinity and God must be
> pretty damn real by now.

Heh. I am not familiar with that particular relationship. But suppose 
that we have ABC and XYZ things in reality, and we claim ABC some 
relation XYZ. Thus, our brains have been thinking of this relation 
between these two (ABC and XYZ) things. Now, if you chant it over and 
over again, that does not make the relation physically expressed, but 
it does in fact make your brain tick in different ways, your mind-brain 
is physical, no? It is processing matter, energy, information, and so 
is making new structs as you go along, thinking about those relations. 
Those new structs are physically there in the brain: think of it like 
electrical storms across millions of neurons and exciting whirlpools of 
viscous, incompressible fluids, kind of like the top of your flakey 
cereal bowl except more exciting than breakfast at five in the morning.

- Bryan
________________________________________
Bryan Bishop
http://heybryan.org/