Re: OT: Doubting Thomas: was "Introducing Myself"

On 17 Feb 2005, at 4.55 pm, Sally Caves wrote:

> What are the odds that a three foot piece of metal as thick as a
> finger and
> propelled by a rocket will fly through your head missing the major
> arteries,
> the areas that control autonomic functioning, the speech center, the
> hippocampus, emerge between the two lobes themselves, and you'll live
> to
> tell about it?  About a trillion to one?
The odds of a three foot piece of metal as thick as a finger existing
is minute, so once we've accounted for that and it going through
someone's skull in the first place, chances are pretty decent that
it'll miss *all* of the autonomic functioning centres, language centres
and the hippocampus, if it's travelling generally upwards from an eye.
The brain isn't arranged with terribly much terribly vital in the
periphery. That'd be stupid.

In particular, if it's going into his right eye and travelling upwards,
leaving between the two lobes, unless his brain is particularly odd,
it's *going* to miss the language centres---we have two of them, but
unlike most of the things we have two of, they're both in the same
hemisphere, almost always the left. It would be more unbelievable if
there was an addendum to the story: 'But unfortunately for him, Phineas
was one of the few people who has their language centres in the right
hemisphere, and his ability to speak was greatly reduced after the
event' (he'd still be able to understand language though, probably).

The brain is a completely amazing part of our body, but it's not
surprising he didn't die; after all, the brain of a rat is incredibly
much smaller, but it keeps the rat alive just as well our massive
brains do.

I will, however, refrain from providing a statistic regarding the odds
of this happening. But if there's say 6.5 billion people alive, and
more people alive today than have existed, there can't've been more
than 13 billion people. If it's happened once, and we can generalise
from past experience, it'd be a mere thirteen billion to one :) --- Of
course, that's not a good way to do statistics :)

> This argument about the P, too, raises some interesting questions
> about the
> nature of belief. Do we have to be present at a scene to believe it?
I see no reason to doubt the story of Phineas. What I know of the brain
seems to make it seem quite reasonable, and if it didn't immortalise
Phineas someone else would've been immortalised instead. Of course, the
people who've told me what I know about the brain are the same people
who've told me about Phineas Gage, and use it as an example of the
nature of the brain, so perhaps I can't trust my knowledge :)

OTOH, being there at the scene makes it harder to apply belief to the
event; if you saw it, you know it, and you have no reason to merely
believe it.

>   Can
> we trust the accounts of medical men of the mid-nineteenth century
> before
> photography was widely used to document things?  Or are we to believe
> that
> everything uncommonly strange is a hoax before we are present to put
> our
> fingers in the wound itself?  For me, the fact that Phineas Gage
> survived
> the accident with memory and intellect intact is about as credible as
> the
> Pirahas and their equally strange development, which may be due just
> as much
> to chance and environment.  We don't need science fiction to find this
> world
> strange enough.
>
> There's a wonderful book out there called _Doubt_ by Jennifer Hecht.
> Doubt
> keeps us honest, to some degree.  Doubt allows us to change.  Taken to
> extreme, though, we can doubt that the astronauts landed on the moon,
> or
> that the earth revolves around the sun or is older than 6000 years.
> So I
> guess my question is... what fixed notions do we have about human
> tribal
> behavior, or human language and cognition that we don't want unsettled?
 From what I know of human language and cognition, I'm prepared to
believe that pretty much anything is possible. We have a few structures
that have no details, but these get filled in with details so that
become so natural that they do become real limitations to the people
involved, and so that the Pirahan seem more than plausible to me.

What I mean is that I find the English language and counting in base 10
so natural that if I'd lived in a bubble for all my life till now, it
seems very likely I'd utter disbelief in the notion that anyone could
possibly *not* speak English, *not* count in base 10, (internally) and
yet still be called a normal human being.

--
Tristan.