h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

No: I said it wasn't logically defensible to state anything *about the Bw* with certainty.

Pattern-chaser

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>>"No: I said it wasn't logically defensible to state anything *about the Bw* with certainty."

Like: "That is a bird"?

I see what he's getting at. One may be mistaken about its being a bird on various grounds...poor eyesight, psychosis, being a disembodied brain in a tank being fed erroneous data...etc. etc. So there's always a possibility that what looks like a duck and quacks like a duck isn't a bird.

What I *don't get is why this is interesting. Where does it take us?

>>"If solipsism could be refuted so easily, it would've been done millennia ago. winkeye Solipsism illustrates a point. That point is more comfortably - for someone raised and educated in 'the West' - shown by Noggin's example: consider that you *could* be a disembodied brain, fed with sensory data corresponding to your experience of an apparently real world. There's no way to tell the difference for certain. Both ezamples illustrate our lack of direct knowledge of our environment: our lack of objective perception."

However, as David Deutsch would argue, solipsism isn't actually *logically defensible*.
If I say 'There's nothing outside *me*', I am forced to conclude that there are simulations within 'me' that do a pretty good job of simulating other people, even people with much more knowledge on a whole range of subjects than 'I' seem to have, and even people who argue against solipsism, and I seem to have no control over how those entities behave.
If I claim those people are imaginations of a 'greater me', I must conclude that there are *parts* of me, possibly a goodly majority, which disagree with solipsism.
If I say there's a 'special me' who really *is* a solipsist, (defining a 'special me' as somewhat akin to how a non-solipsist would define themselves), I must conclude there is a whole world outside the special me which is vastly richer and more complex than the special me actually is.
Even if I consider this world to *still* be part of myself, since introspection is permissible for a solipsist, if I want to understand the world, I use the same methods that I would use were I a realist, and I were looking at the world outside.
Effectively, solipsism is realism weighed down with unnecessary baggage, renaming the world outside to be 'part of a greater me', and renaming objects as thoughts, but still accepting that those thoughts will behave precisely as if they were objects obeying physical laws.

The solipsistic explanation of what I see is at *least* as complicated as the physical explanation, but also requires some inexplicably complicated 'greater me' within which to run all the simulations of reality. Furthermore the solipsistic explanation seems to add nothing whatsoever to an understanding of the world (outside or within).
It is effectively a complete waste of time.

Oh, bravo! That was another argument I was going to make. I didn't realise David Deutsch had already made it. (I should have I remember him from my university psychology).

Yes...solipsism is untenable on neurological grounds. The model of the universe required simply won't fit inside a brain.

Sadly, there's a get-out clause (almost). The solipsist may me fooling her/himself by imagining a brain less large and complex than it really is; fooling her/himself into *thinking* the brain is incapable of the model. HOWEVER: given that the world is observed to be coherent and consistent in all other respects, one has to wonder why the solipsist would choose to lie about this one detail.

I take it you missed my post 8377.

Pattern-chaser

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And yet dreams are convincing....

Solipsism is just an illustration, as is Noggin's example. Does anyone dispute that human perception is not objective, and that therefore we cannot have certain knowledge of any aspect of the Bw?

Pattern-chaser

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I dunno. I turns me back for a couple of minutes and there's 35 new posts!

<>

This remark, and the extended explanation that follows, is exactly right.

But <> is not. We only get to neurology *after* the *logical* untenability of solipsism has been shown. If solipsism were correct, then neurology would be imaginary.

I also note that everybody misunderstood the point of my "brain in a vat" analogy, which was not to show that the brain can be fooled, but to show that the actual nature of reality is unknowable. For the brain in a vat the simulation fulfils all the criteria of reality - it provides a set of inputs that are coherent, and which can be processed into a model of the logical and informational structure
of that external reality.

Noggin

<>

<>

P-C, do we have limited knowledge or not? I don't think anyone is arguing that we do, but I don't know what the hell you're on about any more.

Granted - theoretically, perfectly objective knowledge is beyond us. So what? Are you saying that because we can't have *any* objective knowledge we can't know anything? That's what the first quote says.
Did Italy win the ing game or what?

<>

The *model* will fit inside the human brain. But that there is complexity/detail beyond that contained in the model is part of the model.

Noggin

Hi Pedro,

this is all getting so involved!



No. I'm saying that because we can't have *any* objective knowledge we can't know anything (about the Bw) with certainty.

We know that many things are very probably true, many are very probably false, and more occupy all points in between. But we don't (can't) know anything about the Bw that is certainly true or certainly false.

Pattern-chaser

"Who cares, wins"

>>"I take it you missed my post 8377."

No, I didn't, but "I see a bird" seems basically to be as much of a statement of fact as "It's a bird".

"I see *what appears to* be a bird" would seem to be the kind of thing someone would have to say to satisfy people who were uncomfortable with statements of fact.

In any case the point about the bird/sparrow example still seems lost on me, since you seemed to be using it to illustrate the benefits of *your* Mw/Bw approach, showing how people could avoid making unjustified conclusions from data.

In the sense of nothing being certain, statements about birds and sparrows are uncertain.

In the sense of different kinds of statements being subjectively justifiable by different amounts of fallible evidence, it seems extremely non-earth-shattering to say:
"sometimes we can be fairly confident of one conclusion but less so of a more specific one".
Maybe thinking that way is one inescapable outcome of *your* approach to reality, but it also seems to be the way pretty much anyone sensible would think. Indeed, I'd find it hard to credit you actually thought differently before your ponderings on Mw and Bw.

Absorbing or codifying the implicitly accepted (or the bleeding obvious) may ensure a world-view is not wrong, but may also ensure that people look at it and say "...And?"

<>

But we can. Perhaps not with 100% certainty, but what level of certainty do you want? 99.999999999999999999999999999999999999999999999% just isn't good enough? Is there any doubt whatsoever that Italy didn't win the game tonight? If there is, on what grounds that anyone would take seriously? If there are no grounds to take the doubt seriously, then what use does this uncertainty have? What meaning does it have, come to that? Just because we can't prove everything like a mathematical formula doesn't mean much, to be honest. *And* it's not useful

I take it you mean proving things with 0% probability error/confidence interval type thingy? Well, when you get to zero-point-googol type thingy just how uncertain are you meant to be? What point is there hanging on to the slimmest shred of doubt? Knowing with complete certainty is just how different to knowing within a certain confidence interval? Could the difference be infinitely small, and therefore (objectively) meaningless?


<>

How do you know that for certain?



PS: Ed, isn't David Deutsch a physicist? How come he was mentioned in your psychology class?

Ooh! Others joining in at last! I was begining to bore myself.

Firstly...

>>David Deutsch...physicist...

So I see. I *have* seen some of his stuff - which is relevant to cognitive science - but I'd always assumed he was half of the Deutsch and Deutsch who worked in memory and attention. Seemingly not.

>>Brain in a vat...misunderstood...

I admit that I misused the example above...but I do know where you're coming from. Reality and complete, coherent and consistent Virtual Reality are indistinguishable, So we fundamentally can't know which we inhabit. Right?

But my point is 'So what?' Either way, we inhabit a closed system, so it's useless speculating about what might/ might not lie beyond it.

Similarly...
>>99.999999etc% certainty.

The infinitessimally small remaining fraction is fundamentally unknowable - therefore can be discounted for any useful (practical *or* philosophical) purpose.

Furthermore...here's a fascinating article that explains why 0.9 recurring is identical to 1: http://www.guardian.co.uk/Columnists/Column/0,,1803028,00.html

David Deutsch wrote 'The Fabric of Reality', an above-average book on physics/cosmology, and the blurb says he's a quantum physicist. Although he *does* present an argument in it where he comprehensively demolishes solipsism, so it could well be the same one.

It's the book I'm currently reading - touches on virtual reality as well.

Ed, that article is brilliant. Did you read the comments below it? I like:

"I for one will take Mr PikeBishop’s common sense mathmatics over any amount of pointy headed clatrap from some four–eyes who’s probably working on a thesis about “lesbian algebra” (grant aided no doubt)."

Yes! It's brilliant satire aimed at goading the Guardianistas! Later on he talks about 'Good old British numbers.'

<"I see a bird" seems basically to be as much of a statement of fact as "It's a bird">

I have said nothing about 'statements of fact' as such:

"I see a bird" is a statement of certainty about what I am perceiving; about my own mind. I am quite certain that I am perceiving a bird. [I cannot be sure that my perception of the Bw is accurate, but that's another matter.]

"It is a bird" identifies a Bw element with certainty, which is not logically valid.

P-C:

P:

"It's a bird" was my mistake. I said as much. But it's odd that you didn't realise what I meant. My intended meaning was *implicit*. *Everyone* knows and understands this. Except me. And now you. Either you and I are particularly feeble-minded, or our habitual expressions of certainty are sometimes understood and accepted as such (), and we should mend our ways for the sake of our mental hygiene? No, the latter's just pedantry and nit-picking, after all. It must be the former.

Pattern-chaser

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No, Pedro, please, no! "Certain" is being used here to mean 100% absolute no-question-or-possibility-of-doubt sure.

The difference between 'very very very sure' and 'certain' is that the application of logic is invalid for the former, but valid for the latter.

Pattern-chaser

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