[MD] Probability

[Arlo J. Bensinger]

[Platt to Case]
Here's how my browser responded with absolute certainty to the above: 
 
Your search - > http://en.wikipedia.org/wiki/Brain-in-a-vat - did not match any
documents.

[Arlo]
The link works for me. Maybe your browser is not absolutely certain it is
absolutely certain?

At any rate, the first two paragraphs are reproduced below.

"In philosophy, the brain in a vat is any of a variety of thought experiments
intended to draw out certain features of our ideas of knowledge, reality,
truth, mind, and meaning. It is drawn from the idea, common to many science
fiction stories, that a mad scientist might remove a person's brain from their
body and suspend it in a vat of life-sustaining liquid, and connect its neurons
by wires to a supercomputer which would provide it with electrical impulses
identical to those the brain normally receives. According to such stories, the
computer would then be simulating a virtual reality (including appropriate
responses to the brain's own output) and the person with the "disembodied"
brain would continue to have perfectly normal conscious experiences without
these being related to objects or events in the real world.

The simplest use of brain-in-a-vat scenarios is as an argument for philosophical
skepticism. A simple version of this runs as follows: Since the brain in a vat
gives and receives the exact same impulses as it would if it were in a skull,
and since these are its only way of interacting with its environment, then it
is not possible to tell, from the perspective of that brain, whether it is in a
head or a vat. Yet in the first case most of the person's beliefs may be true
(if he believes, say, that he is walking down the street, or eating ice-cream);
in the latter case they are false. Since, the argument says, you cannot know
whether you are a brain in a vat, then you cannot know whether most of your
beliefs might be completely false. Since, in principle, it is impossible to
rule out your being a brain in a vat, you cannot have good grounds for
believing any of the things you believe; you certainly cannot know them."

Our "births and deaths", then, may simply be the result of a simulated "virtual
reality" program, and although we THINK they are happening to us, our brain is
sitting in some vat somewhere else. Therefore we can never be absolutely
certain that we will (or have) experienced "birth" and "death". Indeed, take
the vat problem one step further and remove the biogenetic component. What if
we are instead part of a giant computer program, each of us "AI's" in a game,
if you will. Our lives (as biological agents) may seem real, but "in reality"
we are simply electronic subroutines in a giant computer somewhere.

Cool.