Could you be a brain in a vat?
Tom Runnacles
world can be conclusively refuted. I've not seen any discussion of this
classic thought-experiment on this newsgroup, so how about it?
Consider the following argument:
(1) If you were a brain in a vat on Mars, sinister Martian scientists
could stimuluate your brain in such a way as to cause your experiences
to be qualitatively indistinguishable from those you are having now.
(2) If you were to know that you are not a brain in a vat on Mars, there
would have to be some feature of your experience which enabled you to
distinguish the case in which you are a brain in a vat on Mars from the
case in which you are not.
So, by (1) and (2):
(3) You do not know that you are not a brain in a vat on Mars.
We can now add a further premise:
(4) For any p and q, if you know that p, and you know that if p then q,
you know q.
From (3) and (4), in conjunction with the premise
(5) If you are sitting in front of a PC reading this newsgroup, you are
not a brain in a vat on Mars
we can infer:
(6) You do not know that you are sitting in front of a PC reading this
newsgroup post.
The premisses of this argument seem pretty plausible, and (I think) the
conclusion in (6) follows deductively from them.
True, the argument presupposes that there is an external world (ie that
you are indeed a brain in a vat on Mars) so it can't generate the most
general type of scepticism. It can, however, generate scepticism about
many of the claims to knowledge about the character of the external
world which we like to make.
Any comments?
Jesus07312
not by any thought process.
They define "truth" only within a certain context of knowledge.
To most people I think, "truth" is almost synonnymous with reality. To
objectivists "truth" is dependant on whatever information that you have. Thus,
someone could make a statement that was not in accord with reality, and by
objectivist standards, it would be considered "true" if it seemed quite likely
from the evidence at hand, regardless of reality.
"Certainty" is the same way. Objectivists define certainty only within what
they already know. An objectivist is certain because the information he has
points to a certain conclusion. Most non-objectivists, I think, are certain
when that believe it is impossible for reality to be any other way, not because
they are certain that information that they have points to a conclusion.
So objectivists say something is "impossible" if they personaly have no
evidence for it.
The whole "your brain CANNOT be in a vat" thing rests on a twisting and
redefining of the english language. When they say "is not possible" they mean
"we have no evidence for it, but of course that could change, and the situation
you describe could eventualy be found to be true, but we will call it
impossible anyway"
-Jesus
Betsy Speicher
> Objectivists seem very confident that scepticism about the external
> world can be conclusively refuted. I've not seen any discussion of this
> classic thought-experiment on this newsgroup, so how about it?
>
> Consider the following argument:
>
> (1) If you were a brain in a vat on Mars, sinister Martian scientists
> could stimuluate your brain in such a way as to cause your experiences
> to be qualitatively indistinguishable from those you are having now.
I don't have any reason to believe that I'm a brain in a vat. Do YOU think
that YOU might be a brain in a vat, Tom? What makes you think so?
Betsy Speicher
You'll know Objectivism is winning when ... you read the CyberNet -- the
most complete and comprehensive e-mail news source about Objectivists,
their activities, and their victories. Request a sample issue at
cybe...@speicher.com or visit http://www.stauffercom.com/cybernet/
Count Lithium von Chloride
>Objectivists seem very confident that scepticism about the external
>world can be conclusively refuted. I've not seen any discussion of this
>classic thought-experiment on this newsgroup, so how about it?
>Consider the following argument:
>(1) If you were a brain in a vat on Mars,
Why a brain in a vat? This still suggests a world not so very
different from the one we believe we live in, with living things and
beings and the need to sustain life. It would seem to me that the
suggestion that we could all be merly computer program generated
consiousnesses operating in a computer program generated world gets at
the heart of the matter a lot better.
>sinister Martian scientists
>could stimuluate your brain in such a way as to cause your experiences
>to be qualitatively indistinguishable from those you are having now.
And Martian scientists could be computer program generated
consiousnesses made to think that they are controling our brains in
vats, but which are in actuality just a part of the computer program
generated world.
>True, the argument presupposes that there is an external world (ie that
>you are indeed a brain in a vat on Mars) so it can't generate the most
>general type of scepticism.
Whatever existence is it exists, i.e., whatever reality is, it is
real.
The proof of this is that we are here and consious. That is, "I think
therefore I am." The mere utterance of which is proof of the matter.
Of course, this in no way means that existence or reality is what we
think it is--simply that it exists and is real.
>It can, however, generate scepticism about
>many of the claims to knowledge about the character of the external
>world which we like to make.
>Any comments?
Whether we are brains in vats or computer program generated
consiousnesses is irrelevant to to the world we we live in, i.e., all
those things that are capable of being studied and messured by us. The
point is, nobody actually believes that they are brains in vats or
computer program generated consiousnesses as nobody behaves as if they
believe they are--i.e., people still go about their daily lives in
sustaining their lives, interacting with others and the world on the
bassis that they believe those things are real.
And moreover, those thing _are_ real, _even_if_ they were just a part
of a computer program generated world--they simply wouldn't be real in
the way we think they are. Intstead of us existing as a mass of atoms
we would in reality exist as as a block of computer program code
operating on a computer.
And how could we know if we aren't computer generated? We wouldn't. We
can never know if we are not computer generated.
Nor could it ever be said that we have evidence that we are not
computer generated, as that so-called "evidence" could be computer
generated. All that can be said is that until we have evidence that we
are computer generated, that there is no reason to believe that it so.
泣┊？㈡
--Count Lithium von Chloride, ushering in the new era
E-mail: vonch...@yahoo.com
Arnold Broese-van-Groenou
Tom Runnacles <th...@elec.qmw.ac.uk> wrote in message
news:3780D25F...@elec.qmw.ac.uk...
> Objectivists seem very confident that scepticism about the external
> world can be conclusively refuted. I've not seen any discussion of
this
> classic thought-experiment on this newsgroup, so how about it?
>
> Consider the following argument:
>
> (1) If you were a brain in a vat on Mars, sinister Martian
scientists
> could stimuluate your brain in such a way as to cause your
experiences
> to be qualitatively indistinguishable from those you are having now.
>
The answer is simple.
The brain isn't the content of the vat.
The vats contents are in the brain.
This causes you to imagine your brain is in a vat.
More seriously. The problem with this setup, is that it sets up a
situation where you are unable to make independent contact with realty
for verification. This is a highly doubtful likelihood. To what extent
do you have volition, and to what extent are your thoughts controlled?
If they are totally controlled, then the question is meaningless.
If not, then you should be able to establish independent thoughts not
put there by Martians. Your discovery of the truth would lie in the
differences between the "reality" the Martians place into your mind,
and the results of independent enquiry into the real world.
--
A.Broese-van-Groenou.
Tony Shrapnel
news:3780D25F...@elec.qmw.ac.uk...
> Objectivists seem very confident that scepticism about the external
> world can be conclusively refuted. I've not seen any discussion of this
> classic thought-experiment on this newsgroup, so how about it?
>
> Consider the following argument:
>
> (1) If you were a brain in a vat on Mars, sinister Martian scientists
> could stimuluate your brain in such a way as to cause your experiences
> to be qualitatively indistinguishable from those you are having now.
>
>
> True, the argument presupposes that there is an external world (ie that
> you are indeed a brain in a vat on Mars) so it can't generate the most
> many of the claims to knowledge about the character of the external
> world which we like to make.
Once a person decides to exercise his or her imagination in this way,
anything is possible. The sinister Martian scientists of which you speak
could themselves be brains in vats on Venus, manipulated at a distance by
sinister scientists on Pluto who are manipulated by geeks on Earth who are
actually the brains in vats on Mars and don't know it. (etc).
The simple fact is that these sorts of arguments are absurd. As such, they
are impossible to refute by use of fact, common sense and logic. For this
reason alone, it is right to be sceptical of the propositions being argued
in such a way.
If a proposition has a genuine possibility of being valid, then arguments
attempting to prove it *could* be plausible. So, I challenge you to produce
a plausible argument to support your proposition. If, in order to produce
logical conclusions supporting your proposition, you must, of necessity,
resort to fantastic premises, then I submit that it is right to reject the
proposition on this ground alone.
Tony Shrapnel
Owl
>(1) If you were a brain in a vat on Mars, sinister Martian scientists
>could stimuluate your brain in such a way as to cause your experiences
>to be qualitatively indistinguishable from those you are having now.
>
>(2) If you were to know that you are not a brain in a vat on Mars, there
>would have to be some feature of your experience which enabled you to
>distinguish the case in which you are a brain in a vat on Mars from the
>case in which you are not.
>
>(3) You do not know that you are not a brain in a vat on Mars.
>
>(4) For any p and q, if you know that p, and you know that if p then q,
>you know q.
>
>(5) If you are sitting in front of a PC reading this newsgroup, you are
>not a brain in a vat on Mars
>
>(6) You do not know that you are sitting in front of a PC reading this
>newsgroup post.
If you look at (4) and (5) more carefully, you'll see that (6) doesn't
follow. If you leave (4) the way it is, then (5) has to be rephrased like
this:
(5') You know that if you are sitting in front of a PC, etc., you are not a
brain in a vat on Mars.
It's fair to ask whether (5') is consistent with skepticism.
Anyway, if you really want to read some serious responses to the argument,
look at the professional literature. Notable would be Putnam's "Brains in a
Vat", Peter Klein's "Skepticism and Closure", and my "Direct Realism and the
Brain in a Vat Argument" (forthcoming in Philosophy and Phenomenological
Research, but that'll take several months).
Ken Stauffer
means your question has no cognitive merit and does not warrant any further
attention. You would need to show some evidence in support of this claim,
before it could be taken seriously.
A better way of phrasing your question could have been this:
"What is mans place in the universe and can we know it?"
I would say that yes we can come to know it, because everything has identity
(even vats and martian scientists).
Ken Stauffer.
Matt Ruff / Lisa Gold
>
> Objectivists seem very confident that scepticism about the external
> world can be conclusively refuted.
Perhaps it can, but I've never seen it conclusively refuted by an
Objectivist.
> Consider the following argument:
>
> (1) If you were a brain in a vat on Mars, sinister Martian scientists
> could stimuluate your brain in such a way as to cause your experiences
> to be qualitatively indistinguishable from those you are having now.
>
> (2) If you were to know that you are not a brain in a vat on Mars,
> there would have to be some feature of your experience which enabled
> you to distinguish the case in which you are a brain in a vat on
> Mars from the case in which you are not.
>
> So, by (1) and (2):
>
> (3) You do not know that you are not a brain in a vat on Mars.
Correct, I don't.
> Any comments?
Well, all else being equal, it seems much simpler to assume that I am
*not* a brain in a vat on Mars -- Occam's razor, y'know. Also, so long
as the illusion is perfect, does it *matter* that it's an illusion?
-- M. Ruff
Gordon G. Sollars
Storyt...@worldnet.att.net writes...
...
> > (3) You do not know that you are not a brain in a vat on Mars.
>
> Correct, I don't.
I think you grant the skeptic far too much, Matt. What reason would you
have for thinking that you were a brain in a vat on Mars that would be
different from your thinking that you were a brain in a vat on Venus?
> > Any comments?
>
> Well, all else being equal, it seems much simpler to assume that I am
> *not* a brain in a vat on Mars -- Occam's razor, y'know. Also, so long
> as the illusion is perfect, does it *matter* that it's an illusion?
Robert Nozick considers this in /Anarchy, State, and Utopia/ when he
talks about an "experience machine". Wouldn't you be troubled to learn
that it had been a perfect illusion that you had written SG&E?
--
Gordon Sollars
gsol...@virginia.edu
Tom Runnacles
As to the literature you mention, I know Putnam's paper and Nozick's
stuff (though not Klein's) , but I've always found Thomas Nagel's line
in 'The View from Nowhere' on this kind of thing the most plausible:
that anti-sceptical arguments based on views about reference rebound on
their proponents, ie that if your view about the possibility of
reference rules out scepticism, that refutes not scepticism but your
view about reference.
I posted this (concededly botched) version of the brain in the vat
argument simply to try to provoke a response: I just wanted to know what
Objectivists would do with it.
I'd be v. interested to know more about your position, btw.
Tom
>
> If you look at (4) and (5) more carefully, you'll see that (6) doesn't
> follow. If you leave (4) the way it is, then (5) has to be rephrased like
> this:
>
> (5') You know that if you are sitting in front of a PC, etc., you are not a
> brain in a vat on Mars.
>
Tom Runnacles
> > (1) If you were a brain in a vat on Mars, sinister Martian scientists
> > could stimuluate your brain in such a way as to cause your experiences
> > to be qualitatively indistinguishable from those you are having now.
> >
> >
> > The premisses of this argument seem pretty plausible, and (I think) the
> > conclusion in (6) follows deductively from them.
>
> disembodied brains in vats on Mars, and sinister Martian
> scientists are manipulating our thoughts! HA! HA!
>
> > Any comments?
>
> No wonder Objectivists don't take skeptics seriously.
What I said was that the premise that IF you were a brain in a vat, THEN
your brain could be stimulated in an appropriate manner to produce the
same experiences you are presently having. I don't need the claim that
it's plausible that you ARE a brain in a vat here, since the conditional
can come out true even if its antecedent is false.
Perhaps if you read what I said a little more carefully, you might
reconstruct my argument more accurately and understand it a little
better before dismissing it in so cavalier a fashion.
Joe Durnavich
>Objectivists seem very confident that scepticism about the external
>world can be conclusively refuted. I've not seen any discussion of this
>classic thought-experiment on this newsgroup, so how about it?
>
>Consider the following argument:
>
>(1) If you were a brain in a vat on Mars, sinister Martian scientists
>could stimuluate your brain in such a way as to cause your experiences
>to be qualitatively indistinguishable from those you are having now.
This would be a hell of a premise to prove right? COULD a group of
scientists actually simulate your environment to such an extent that
you couldn't tell? (I'm assuming that the switch occurs sometime
during your life.) They would have to program in just about every
fact about every person on Earth and every location. I can go just
about anywhere from Muncie, Indiana to visiting the Titanic at the
bottom of the Atlantic. I can study microorganisms under a
microscope, look at old family photos, talk to my family about my
childhood, watch my favorite Simpsons re-runs. And my coffee better
taste right. I like it strong with a good kick to it.
Would it be feasible for them to capture and record this information
and be able to build a computer that can run such a detailed
simulation? Your premise--that scientists *could* do this--places a
very heavy burden on you to prove.
That said, I have read about scientists (Earth ones), that have
tricked bats by sending the right ultrasonic sounds to give the bats
an impression that they were approaching a ledge. The bats would try
to land on this "ledge" which was nothing but thin air. But it's a
long way from simulating a ledge to simulating just about everything.
--
Joe Durnavich
Tony Shrapnel
> Anyway, if you really want to read some serious responses to the argument,
> look at the professional literature. [snip]
Could you please explain to us exactly what you mean by "serious responses"?
Tony Shrapnel
Steven Smolinski
>Objectivists seem very confident that scepticism about the external
>world can be conclusively refuted. I've not seen any discussion of this
>classic thought-experiment on this newsgroup, so how about it?
>
>Consider the following argument:
Christ, you're cutting and pasting from a first-year philosophy course.
Consider the following objection: ad ignorantiam. One need only consider
those premises for which at least some evidence has been adduced. I'm not
going to go into a whole thing here, but what would it mean if you gave
every statement uttered credence *simply* because it was said? Why think
about it? There's literally no*thing* to think about until some connection
to reality has been shown or attempted.
So to your first premise, that I may be a brain in a vat, I say: I won't
even consider past that point until some credible evidence points in that
direction.
And if you *really* thought such utterings were credible, you would have
been typing that post of yours thinking "I wonder if the aliens have
covered off replicating usenet as well!! I'll see what answers the aliens
make the fake people fabricate!!" In fact, I suspect you wrote the post
to get responses by real, thinking people, not because it may trick the
aliens' brain-altering technology.
If that's the case, then even you (properly) don't buy your own premise.
So why expect anyone else to buy it? Why don't you ask, rather, why you
think something is 'logical' even though by your actions, you don't buy it?
Contradictions like that point to an error. Don't question why you're not a
brain in a vat; question your questionable philosophy training.
Steve
P.S. I may seem somewhat impatient here, but this one really is too common and
too silly for me not to get a little irked. Or maybe the aliens just 'tweaked'
my brain that way just this moment... [sheesh]
Chris Wolf
>So to your first premise, that I may be a brain in a vat, I say: I won't
>even consider past that point until some credible evidence points in that
>direction.
My vat needs changing.
Chris Wolf
cwo...@nwlink.com
Check out the World's Fastest Keyboard!
http://www.jeffcomp.com/jcp/
What's REALLY wrong with Objectivism
http://www.jeffcomp.com/jcp/faq/
My Dinner With Andy
http://www.jeffcomp.com/jcp/faq/dinner.html
Tony Shrapnel
news:3782c18e....@news.supernews.com...
> Steven Smolinski writes:
>
> >So to your first premise, that I may be a brain in a vat, I say: I won't
> >even consider past that point until some credible evidence points in that
> >direction.
>
> My vat needs changing.
How do you know?
Tony Shrapnel
Tony Shrapnel
Tom Runnacles <th...@elec.qmw.ac.uk> wrote in message
news:3780D25F...@elec.qmw.ac.uk...
[snip]
> Consider the following argument:
>
> (1) If you were a brain in a vat on Mars, sinister Martian scientists
> could stimuluate your brain in such a way as to cause your experiences
> to be qualitatively indistinguishable from those you are having now.
(a) In order for (1) to possibly be true, at least the planet Mars, my brain
in a vat, and a sinister Martian scientist would have to exist.
(b) If these things existed, they would have the potential to be destroyed.
> (2) If you were to know that you are not a brain in a vat on Mars, there
> would have to be some feature of your experience which enabled you to
> distinguish the case in which you are a brain in a vat on Mars from the
> case in which you are not.
(c) If (1) was true, then "I" could not possibly have free will.
(d) If (1) was true, then the Martian scientist in control would not want to
be destroyed, so he would not direct or allow "me" to destroy him.
(e) But, if I exercise my free will, and launch this new Mars-destroying
whoompher-weapon that I have *just invented*, right here in front of my PC
(which I may certainly be permitted to do, as that is just as plausible as
my brain being in a vat on Mars), then I can destroy Mars and everything on
it, and watch as it happens, which I will now do...
(f) *** WHOOMPH !!! ***
(g) Now Mars and everything on it has been totally destroyed, but I am still
here.
>
> So, by (1) and (2):
>
> (3) You do not know that you are not a brain in a vat on Mars.
On the contrary, by (a), (b), (c), (d), (e) (f) and (g):
(h) I definitely *know* that I am *not* a brain in a vat on Mars.
[snippagis - 'nuff said - argument won!]
Tony Shrapnel
Chris Wolf
>> My vat needs changing.
>How do you know?
Some of Jim Klein's posts started to sound reasonable.
jon_l...@my-deja.com
Steven Smolinski <s...@YorkU.CA> wrote:
>
> So to your first premise, that I may be a brain in a vat, I say: I
won't
> even consider past that point until some credible evidence points in
that
> direction.
>
Evidence that I'm a brain in a vat:
If this universe were real then the following things would
probably be true:
1) An exponential technological explosion would be occurring.
2) This universe would last at least another 12 billion years.
3) Eventually (perhaps as soon as the 21st Century) entire lives
would be experienced in virtual reality.
4) The information (DNA) to make 5 billion baby Newtons,
Darwins, and Einsteins could be contained in one teaspoon.
5) The information to perform one entire life such as my own
could probably also be contained in one teaspoon. (Moravec
claims all of human history could be contained in a pea.)
Therefore more lives would eventually be lived virtually than
organically (IF this universe were real.)
Therefore my life is more likely to be virtual than organic.
]]]]]]]]]]]]]]]]]]]
What would be the most interesting time to live a virtual life?
It would be in the days when _The Selfish Gene_ was first
discovered and virtual reality was first invented, and then you
would see what you can do to make your avatar help avoid
Universal Wars III through MMCXI.
What could you do to make your avatar help avoid Universal
Wars III through MMCXI?
Cause him to Promulgate Good's Golden Rule:
(Paraphrasing)
"Start treating the animals with respect if you want the gods to
treat you with respect."
]]]]]]]]]]]]]]]]]]]]]]
Web Pages:
I. J. Good
Irving John Good
Vernor Vinge
http://www-rohan.sdsu.edu/faculty/vinge/misc/singularity.html
(next is slightly different)
http://www-personal.engin.umich.edu/~jxm/singlar.html
http://128.173.40.129/~history/Good.html
Hans Moravec
http://www.frc.ri.cmu.edu/~hpm/project.archive/general.articles/1993/Rob
ot93.html
http://www.wired.com/wired/archive/3.10/moravec.html
]]]]]]]]]]]]]]]]]]]]]]]]]]]]]
Jon Larson
jon_l...@my-dejanews.com
pka
vr...@my-dejanews.com
********
Also, my rules:
"You can't send anyone to eternal hell for more than one week."
"Pinch the head off anyone who catches fish with a hook."
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
Jesus07312
>been typing that post of yours thinking "I wonder if the aliens have
>covered off replicating usenet as well!! I'll see what answers the aliens
>make the fake people fabricate!!" In fact, I suspect you wrote the post
>to get responses by real, thinking people, not because it may trick the
>aliens' brain-altering technology.
Ayn and many objectivists make this mistake often. They think that if you admit
that something is not impossible, then you consider it equaly with things you
have evidence for. One can say "Sure, there is a very small chance that this
could be true" Without making decisions based on the fact that an alien is
controlling them.
-Jesus
Jesus07312
>whoompher-weapon that I have *just invented*, right here in front of my PC
>(which I may certainly be permitted to do, as that is just as plausible as
>my brain being in a vat on Mars), then I can destroy Mars and everything on
>it, and watch as it happens, which I will now do...
>
>(f) *** WHOOMPH !!! ***
>
>(g) Now Mars and everything on it has been totally destroyed, but I am still
>here.
But the alien and his device could be made out of an invisible, industructable
energy field.
-Jesus
Jesus07312
>(a) In order for (1) to possibly be true, at least the planet Mars, my brain
>in a vat, and a sinister Martian scientist would have to exist.
Wrong. Your finite human mind may not understand how the alien could not exist,
yet still control you. OF course this seems impossible to you. But keep in mind
you are just a little single celled organism compared to the enormous power and
complexity of this alien.
>(b) If these things existed, they would have the potential to be destroyed.
Wrong. Even if the alien did exist, you could not deduce that you could detroy
it. Maybe it exists in some higher plane or dimension, maybe, as I said
earlier, the alien does exist as you think he does but he is invisible, has no
mass, and is indestructable.
>On the contrary, by (a), (b), (c), (d), (e) (f) and (g):
>
>(h) I definitely *know* that I am *not* a brain in a vat on Mars.
>
>[snippagis - 'nuff said - argument won!]
>
Wrong. You cannot know (a) and (b) (or any of your other premises, which I did
not take the time to show). You've lost the argument. Try again.
-Jesus
Owl
>stuff (though not Klein's) , but I've always found Thomas Nagel's line
>in 'The View from Nowhere' on this kind of thing the most plausible:
>that anti-sceptical arguments based on views about reference rebound on
>their proponents, ie that if your view about the possibility of
>reference rules out scepticism, that refutes not scepticism but your
>view about reference.
Yeah, I don't accept the causal theory of reference anyway; I just think
it's something interesting to think about. As you probably know, there's a
lot of debate about whether the causal theory really has the implications
Putnam says. But I think Putnam has a dilemma: if the causal theory can be
used to prove that we're not BIV's, based on just the premise that the word
"brain" is meaningful, then I think it should also be usable to obtain lots
of other a priori knowledge that we don't want. (E.g., you could prove a
priori that dinosaurs existed, or perhaps that God exists, just because the
words "dinosaur" and "God" are meaningful.) But let's not go into that.
>I posted this (concededly botched) version of the brain in the vat
>argument simply to try to provoke a response: I just wanted to know what
>Objectivists would do with it.
When students hear about the BIV argument, there are generally three sorts
of reactions. The first sort of student gets worried, because hey, maybe I
am a BIV. I guess I really can't know.
The second sort of student thinks, "No, that can't be right" and tries to
figure out what's wrong with it.
The third sort of student says, "God, this is stupid. Can we talk about
something else?"
Most Objectivists are of the third type. I was of the first type; then,
later, of the second type.
Anyway, here's a couple of things to think about. First, think about
philosophy of science. Say you're considering a theory that explains some
evidence. Theories generally don't explain (or predict) any observations
all by themselves; they explain something in the context of the rest of our
background knowledge. If you changed the background assumptions, the theory
might have different predictions. Now, what happens if you have a theory
that allegedly predicts observation O (an observation we have in fact made),
but that also implies that the background assumptions necessary to make that
prediction are false, unjustified, or unreliable? That's a problem.
Well, the BIV hypothesis allegedly predicts that you would be having sensory
experiences similar to your present experiences. Why? Because we know from
scientific experiments that sensory experiences are caused by electrical
stimulation of certain portions of the brain; therefore, if you stimulated a
brain artificially in exactly the right pattern, it should have the same
experiences. (That's why it's the brain-in-a-vat hypothesis, not the
spleen-in-a-vat hypothesis.) But the BIV hypothesis, itself, implies that
the evidence on which I'm basing this prediction is false (i.e., the
observations I think I made were all illusory). So the hypothesis
undermines its own claim to explanatory power.
That's not what I said in my paper, though. In my paper, I said that the
BIV argument only undermines indirect realist theories of perceptual
knowledge. But to explain that requires first going through Peter Klein's
response (which is pretty good - I seriously recommend reading it).
o
Arnold Broese-van-Groenou
Tony Shrapnel <shra...@ozemail.com.au> wrote in message
news:JSDg3.154$9W6...@ozemail.com.au...
> (e) But, if I exercise my free will, and launch this new
Mars-destroying
> whoompher-weapon that I have *just invented*, right here in front of
my PC
> (which I may certainly be permitted to do, as that is just as
plausible as
> my brain being in a vat on Mars), then I can destroy Mars and
everything on
> it, and watch as it happens, which I will now do...
>
> (f) *** WHOOMPH !!! ***
>
> (g) Now Mars and everything on it has been totally destroyed, but I
am still
> here.
I will play devils advocate here Tony.
One Martian turns to the other and says:
Nice programming Zog.
You got him to believe he destroyed us with a missile.
This will get you a professorship for sure.
--
A.Broese-van-Groenou.
db...@tampatrib.com
Tom Runnacles <th...@elec.qmw.ac.uk> wrote:
> Objectivists seem very confident that scepticism about the external
> world can be conclusively refuted.
Who seems confident? People other than yourself?
> I've not seen any discussion of this
> classic thought-experiment on this newsgroup, so how about it?
Discussion by whom? Other people?
> Consider the following argument:
To whom are you talking?
-- at no extra charge
db...@tampatrib.com
Jesus07312 <jesus...@aol.com> wrote:
> Tom, objectivists "refute" this by changing the definitions of common words,
> not by any thought process.
Who refutes the "brain-in-a-vat" scenario? Someone other than yourself?
> The whole "your brain CANNOT be in a vat" thing rests on a twisting and
> redefining of the english language.
Redefining by whom?
Steven Smolinski
>In article <931305263...@newshub.ccs.yorku.ca>,
> Steven Smolinski <s...@YorkU.CA> wrote:
>> So to your first premise, that I may be a brain in a vat, I say: I
>won't
>> even consider past that point until some credible evidence points in
>that
>> direction.
>Evidence that I'm a brain in a vat:
>If this universe were real then the following things would
>probably be true:
>1) An exponential technological explosion would be occurring.
>2) This universe would last at least another 12 billion years.
>3) Eventually (perhaps as soon as the 21st Century) entire lives
>would be experienced in virtual reality.
>4) The information (DNA) to make 5 billion baby Newtons,
>Darwins, and Einsteins could be contained in one teaspoon.
>5) The information to perform one entire life such as my own
>could probably also be contained in one teaspoon. (Moravec
>claims all of human history could be contained in a pea.)
>Therefore more lives would eventually be lived virtually than
>organically (IF this universe were real.)
>Therefore my life is more likely to be virtual than organic.
I think that people who have modern philosophy degrees should not be wasted, as
many currently are, as McDonald's caashiers. I believe they make much better
comedians.
Steve
botfood
botfood
botfood
botfood
botfood
botfood
Jesus07312
By objectivists. They take a word like "impossible" which to most people means
"under no circumstances could this be real, period." and give it a new meaning
like "it cannot be real within the context of my limited knowledge." Then they
procede to use the word "impossible" with non-objectivists without telling them
about the new meaning. They also get upset and call the person that are talking
to "evil" and "evasive" and "immoral" because this person has no idea that the
objectivist has taken it upon himself to alter the meaning of words.
-Jesus
Joe Durnavich
>When students hear about the BIV argument, there are generally three sorts
>of reactions. The first sort of student gets worried, because hey, maybe I
>am a BIV. I guess I really can't know.
>
>The second sort of student thinks, "No, that can't be right" and tries to
>figure out what's wrong with it.
>
>The third sort of student says, "God, this is stupid. Can we talk about
>something else?"
>
>Most Objectivists are of the third type. I was of the first type; then,
>later, of the second type.
Objectivists don't need to be of the third type because the BIV
argument, as usually presented, commits the "stolen concept" fallacy.
For example, if one argues that all his knowledge derived from
experience is unreliable because he could be a BIV, then how did he
find out about brains, vats, senses, methods to fool them, etc?
--
Joe Durnavich
db...@tampatrib.com
Jesus07312 <jesus...@aol.com> wrote:
> >Redefining by whom?
>
> By objectivists.
So, Objectivists exist?
Jesus07312
Obviously. Your point?
(if you try to claim that I can't be "certain" or something, by my own
admission, and thus I shouldn't claim they exist, you'll be refuted.)
-Jesus
Matt Ruff / Lisa Gold
>
> Matt Ruff wrote:
>
>>> (3) You do not know that you are not a brain in a vat on Mars.
>>
>> Correct, I don't.
>
> I think you grant the skeptic far too much, Matt. What reason would
> you have for thinking that you were a brain in a vat on Mars that
> on Venus?
None that's different. There's no positive evidence for either; merely a
lack of omniscience on my part that prevents from saying, with absolute
certainty, that neither is true.
>> ...all else being equal, it seems much simpler to assume that I am
>> *not* a brain in a vat on Mars -- Occam's razor, y'know. Also, so
>> long as the illusion is perfect, does it *matter* that it's an
>> illusion?
>
> Robert Nozick considers this in /Anarchy, State, and Utopia/ when he
> talks about an "experience machine". Wouldn't you be troubled to
> learn that it had been a perfect illusion that you had written SG&E?
But that's the whole point; if the illusion is perfect, I *can't* learn
it.
-- M. Ruff
jon_l...@my-deja.com
Steven Smolinski <s...@YorkU.CA> wrote:
I'm not too familiar with flaming. When a botfood
attacks your occupation instead of your arguments
does that mean he admits defeat?
Or does it just mean he's chicken?
Gordon G. Sollars
Storyt...@worldnet.att.net writes...
> Gordon G. Sollars wrote:
...
> > you have for thinking that you were a brain in a vat on Mars that
> > would be different from your thinking that you were a brain in a vat
> > on Venus?
>
> None that's different. There's no positive evidence for either; merely a
> lack of omniscience on my part that prevents from saying, with absolute
> certainty, that neither is true.
What do you mean by "absolute certainty"? Do you mean the certainty that
comes from a logical deduction? Even there a mistake can be made. So
what is "absolute certainty"? When do you know that you have it?
As a good pragmatist, I don't think that is a very interesting notion of
certainty. Objectivists agree with pragmatists here, of course, when
they deny the acceptability of a "standard of omniscience".
...
> > Robert Nozick considers this in /Anarchy, State, and Utopia/ when he
> > talks about an "experience machine". Wouldn't you be troubled to
> > learn that it had been a perfect illusion that you had written SG&E?
>
> But that's the whole point; if the illusion is perfect, I *can't* learn
> it.
Why does "perfect illusion" imply "perfectly sustainable illusion"? In
any event, the whole idea of counterfactual examination is to think about
what would be true. Now I would be the first to admit that
counterfactuals can be carried too far; many contemporary philosophers,
especially moral philosophers, overuse them. There are many possible
worlds that I take to be unreachable, casually, from this one. So
concern over them is not well placed, IMHO. But we are already well out
on a casual limb when we are taking about brains in vats and experience
machines.
You asked "what difference it would make". In fact, I suspect it would
make a big difference to you. You are certain that you wrote SG&E, at
least as certain as you are of anything else. And I further suspect that
it would trouble you to consider that it was possible that you could
learn that you did not, but were only manipulated into thinking that you
had.
--
Gordon Sollars
gsol...@virginia.edu
Rod Nibbe
> You are certain that you wrote SG&E, at
> least as certain as you are of anything else. And I further suspect that
> it would trouble you to consider that it was possible that you could
> learn that you did not, but were only manipulated into thinking that you
> had.
If you discover that Matt Ruff has been duped, if he's really just an
instance of "Truman" and not the author of SG&E, if in fact the book is
apocryphal, would you e-mail me quick? I won't bother to show up for the
book signing.
-RKN
(rni...@alaska.net)
Owl
>Objectivists don't need to be of the third type because the BIV
>argument, as usually presented, commits the "stolen concept" fallacy.
>For example, if one argues that all his knowledge derived from
>experience is unreliable because he could be a BIV, then how did he
>find out about brains, vats, senses, methods to fool them, etc?
Well, that's sort of what I was saying at the end of the message.
The skeptic could make one of two responses:
First, the skeptic could say, "I never said you 'found out' about brains,
etc. (where finding out implies having knowledge). I just said it was
possible that you were a BIV (the scenario can be described consistently,
and there is no evidence against it). Of course, it is also possible that
there's no such thing as a brain; or that there are brains, but they have
nothing to do with consciousness. In which case you might be a kidney in a
vat, or something else. But whatever it is that causes consciousness
(whether brain stimulation or something else), it is possible for conscious
states to exist without their corresponding to real things."
Second, the skeptic could say: "I'm giving a _reductio ad absurdum_ of the
common sense beliefs. In the reductio ad absurdum form of argument, you
assume your opponent's view, and then show how it leads to contradictions or
other absurdities. So, I'm saying that if you assume the common sense
views, in which the senses are reliable, and we have knowledge of the
physical world, including knowledge about brains, etc.; then you can also
infer from those very assumptions, that it would not be possible to know
anything about the physical world." Assuming A, and showing that it leads
to not-A, is often a useful method of refuting A.
db...@tampatrib.com
Jesus07312 <jesus...@aol.com> wrote:
> >So, Objectivists exist?
>
> Obviously.
So, you obviously aren't a brain in a vat.
-- at no extra charge
Jesus07312
But I am not "Certainly" not a brain in a vat.
-Jesus
db...@tampatrib.com
Jesus07312 <jesus...@aol.com> wrote:
> >So, you obviously aren't a brain in a vat.
>
> But I am not "Certainly" not a brain in a vat.
Well, hang on a minute. Are you criticizing Objectivists, or not?
Jesus07312
>
Of course, I am saying they redefine words without telling anyone, which they
do.
-Jesus
Chris Wolf
If they don't tell anyone, then how do you know about it?
Unless, of course, you are secretly an Objectivist.
Hmmm?
Joe Durnavich
>Joe Durnavich wrote in message <37840e0b...@news.mcs.net>...
>
>>Objectivists don't need to be of the third type because the BIV
>>argument, as usually presented, commits the "stolen concept" fallacy.
>>For example, if one argues that all his knowledge derived from
>>experience is unreliable because he could be a BIV, then how did he
>>find out about brains, vats, senses, methods to fool them, etc?
>
>
>Well, that's sort of what I was saying at the end of the message.
Yeah, I saw that. I just thought it interesting that the O'ists
possess a perfectly good argument against the BIV scenario, but as you
pointed out, most didn't want to discuss the issue.
>The skeptic could make one of two responses:
>
>First, the skeptic could say, "I never said you 'found out' about brains,
>etc. (where finding out implies having knowledge). I just said it was
>possible that you were a BIV (the scenario can be described consistently,
>and there is no evidence against it). Of course, it is also possible that
>there's no such thing as a brain; or that there are brains, but they have
>nothing to do with consciousness. In which case you might be a kidney in a
>vat, or something else. But whatever it is that causes consciousness
>(whether brain stimulation or something else), it is possible for conscious
>states to exist without their corresponding to real things."
In one of his books, Woody Allen had a course listing for a fictional
college. For the description under Epistemology 101 he has, "Is
knowledge knowable? If not, how do we know this?" This is
essentially the problem with the skeptic's argument. The skeptic
needs a foundation of knowledge to stand on just like everybody else,
even though he may use that foundation to deny its very existence.
For the argument above, the question, "How did you find out?" would
still need to be answered. The skeptic says it is possible to be a
brain in a vat. Alright, just how did he find out that was indeed
possible? How did he find out conscious states could exist without
them corresponding to real things? His conclusions will always
presuppose a direct knowledge of the world arrived at through the use
of his senses.
>Second, the skeptic could say: "I'm giving a _reductio ad absurdum_ of the
>common sense beliefs. In the reductio ad absurdum form of argument, you
>assume your opponent's view, and then show how it leads to contradictions or
>other absurdities. So, I'm saying that if you assume the common sense
>views, in which the senses are reliable, and we have knowledge of the
>physical world, including knowledge about brains, etc.; then you can also
>infer from those very assumptions, that it would not be possible to know
>anything about the physical world." Assuming A, and showing that it leads
>to not-A, is often a useful method of refuting A.
It wouldn't follow though, that because you were able to learn about
senses and brains and the methods to fool them that you can really
know nothing about the world. To learn about how your eyes work, you
have to look at something first. It wouldn't follow that because you
saw trees, forests, swans, billiard balls, bachelors, and vats, that
your eyes really can't see anything at all.
However, one variation on the argument that may work is the idea that
your friends--the evil genius ones--drugged and kidnapped you a few
months ago and hooked your brain up to a simulator. The problem is
to see if you can detect that this has occurred. This is usually not
the problem the skeptic proposes, though, who wishes to drive a wedge
between the mind and reality at a fundamental level. The problem is
more like what an art dealer has to go through to determine if a
particular piece of art is a forgery. Even the experts get fooled.
But it doesn't follow that because forgery experts are mistaken from
time to time that everything can fundamentally be a forgery.
Of course, the skeptics can just say they don't have a problem with
making non-contradictory arguments. And this is why they are
bastards.
--
Joe Durnavich
db...@tampatrib.com
Jesus07312 <jesus...@aol.com> wrote:
> >Well, hang on a minute. Are you criticizing Objectivists, or not?
> Of course, I am saying they redefine words without telling anyone, which they
> do.
So, you aren't a brain in a vat.
Jesus07312
I don't think I am, but I am not "certain." You do not need to be certain of
something in order to form beliefs about how things most likely are.
I don't need to be certain to tell you that if I roll a 50 sided dice 100 times
consecutively, the sum off all of my roles will be greater than 101. Even
though I am not certain, acting on any premise other than "the sum of the rolls
will be over 101" is foolish. Just as acting on the premise that you are a
brain in a vat(if you'd act any differently) is foolish.
Jesus07312
>they
>>do.
>
>
>Unless, of course, you are secretly an Objectivist.
Or unless of course, I read OPAR and see how Peikoffs explanations are false
without him having to introduce nonstandard meanings for certain words like
"true" "certain" "possible" etc.
-Jesus
Joe Durnavich
>Or unless of course, I read OPAR and see how Peikoffs explanations are false
>without him having to introduce nonstandard meanings for certain words like
>"true" "certain" "possible" etc.
Acutally, Piekoff's uses of these terms is pretty much how people use
them in everyday life. People make statements all the time like, "I
am certain I left my car keys on the kitchen table." It is
philosophers who give the word "certain" a useless meaning.
--
Joe Durnavich
Jesus07312
>them in everyday life. People make statements all the time like, "I
>am certain I left my car keys on the kitchen table."
And when they say that, they really do mean that "I left my keys on thew table.
Reality is not any other way, period."
They don't mean the objectivist definition of certainty: "As far as I know, I
left them on the table, but reality could be different."
-Jesus
Owl
>For the argument above, the question, "How did you find out?" would
>still need to be answered. The skeptic says it is possible to be a
>brain in a vat. Alright, just how did he find out that was indeed
>possible? How did he find out conscious states could exist without
>them corresponding to real things? His conclusions will always
>presuppose a direct knowledge of the world arrived at through the use
>of his senses.
I think you have to distinguish between two kinds of skeptics. First, the
'global skeptic' says that nothing whatsoever is knowable. This implies
that the statement that nothing is knowable, itself is not knowable.
But, second, the 'external world skeptic', in contrast, says no contingent
proposition about the external world is knowable. That not contingent
proposition about the external world is knowable, the skeptic will say, is
not itself a contingent proposition about the external world. Therefore, it
does not imply that it is not itself knowable.
In answer to the question of how we know external world skepticism to be
true, there is the brain-in-a-vat argument, which has already been stated.
As to how we know that such-and-such is possible, the skeptic will say that
the 'possibility' of x is a merely negative fact: it means that x has not
been (or, cannot be) proven to be false. As a result, the burden of proof
is on he who says x is not possible.
>It wouldn't follow though, that because you were able to learn about
>senses and brains and the methods to fool them that you can really
>know nothing about the world. To learn about how your eyes work, you
Well, I agree with you; the skeptic, however, thinks that it does follow.
Why not? You've already seen the argument by which we get to that
conclusion.
>have to look at something first. It wouldn't follow that because you
>saw trees, forests, swans, billiard balls, bachelors, and vats, that
>your eyes really can't see anything at all.
The skeptic, if he knows his business, does not say, "You can never see
anything." The skeptic says that you never know whether a particular sort
of physical object exists or not. As a result, you never know whether you
are seeing things or merely hallucinating things. The skeptic doesn't argue
that you are a brain in a vat, in actual fact. He only says that you
*might* be one. If, in fact, you're not one, then you see things all the
time (even though you don't know it).
o
Chris Wolf
>>In article <19990708211558...@ng-cg1.aol.com>,
>> Jesus07312 <jesus...@aol.com> wrote:
>>
>> Of course, I am saying they redefine words without telling anyone, which
>> they
>> do.
>So, you aren't a brain in a vat.
I decided to go and look for myself. I found a small brown object,
floating in a pool of liquid, in a white vat labeled "Jesus."
I was going to investigate further, and try to communicate with it, but
somebody flushed the vat.
End of investigation.
Joe Durnavich
>The skeptic, if he knows his business, does not say, "You can never see
>anything." The skeptic says that you never know whether a particular sort
>of physical object exists or not. As a result, you never know whether you
>are seeing things or merely hallucinating things. The skeptic doesn't argue
>that you are a brain in a vat, in actual fact. He only says that you
>*might* be one. If, in fact, you're not one, then you see things all the
>time (even though you don't know it).
This is the representational model of perception stated in the
skeptic's vague, indecisive, but suggestive way. Once again the
skeptic has to adopt a privileged position to know about the true
relation between our perception and reality, namely, that our
perceptions are mediated by a wall of possible error, delusion, and
hallucination.
Consider that every single word and concept the skeptic utters, he had
to learn through a process of observing and reasoning about the
external world. He learned concepts like "possible," "contingent,"
"proof," "true," "false," etc. using the very process he has so many
doubts about. The conclusions he draws about what might or might not
be the case are based on the same knowledge, even the ones he says are
not contingent. For example, one must learn arithmetic by first
learning to count physical, external objects. It would be
contradictory, then, to say that arithmetic truths are necessarily
certain, but any knowledge based on observation is in doubt. To do so
is to steal the concepts of numbers, addition, identity, etc.
Admittedly, it is quite easy to cut loose from the genetic roots of
our existing knowledge and lose sight of how we came to know what we
know.
The skeptic is right in that you can't prove the direct model of
perception because to do so leads to a circular argument. The
skeptic, however, as would any representationalist will have to adopt
the direct model to make their case against it. Consider the case of
hallucinations. How did the skeptic find out about hallucinations?
(1) He observed subjects suffering hallucinations who stated they saw,
say, lizards running around the room when the skeptic saw that no
lizards were in the room. Or, (2), the skeptic periodically suffers
from hallucinations himself when Jesus appears to him and instructs
him to start the fires. The only way to know that was a hallucination
is to know that Jesus wasn't really there at the time. In both cases,
the argument from hallucinations, and the concept "hallucination," is
derived from a context of direct, normal, perception.
Another way to look at this is this: I just looked at my coffee cup
and I saw that it was empty. That's about a simple and direct
observation as they come. The skeptic says I might be wrong about
this because of the possibility of hallucinations, BIVs, error, etc.
His knowledge of these things are based on many, many, more
observations than my simple single observation. How could it be that
his sophisticated scientific discoveries of the features of perception
are more certain than my simple observation about my coffee cup?
The skeptic may counter that even his ideas are in doubt, that as you
say, hallucinations "might" be happening. Well, here's a guy who is
in doubt about just about everything; who can't tell if he is
hallucinating or not; whose entire base of knowledge is tainted with
the possibility of error; and who may be cognitively isolated from
reality. He doesn't give us much reason to listen to him, does he?
The idea of the brain in the vat also doesn't support the skeptic's
claims about the nature of perception. The function of our perceptual
faculties is to become aware of features in the world. What an object
looks like to us depends on the nature of the object, and the nature
of our senses, brain, etc. What if you were a BIV? Rather than
perceiving objects in the world, you would be perceiving states in a
simulator. These states in the simulator might be different voltage
levels stored in a multitude of transistors. These voltages are every
bit as real as trees and horses. The way these voltages states appear
to you, with colors and shapes of trees and horses are how they are
supposed to look given your perceptual facilities. There is no "true
look" intrinsic to a voltage state, no one way they are supposed to
look. If you were a BIV, you would be discriminating real features in
the simulator and be able to derive knowledge from them by observing
them--the very act the skeptic denies.
--
Joe Durnavich
db...@tampatrib.com
Jesus07312 <jesus...@aol.com> wrote:
> >So, you aren't a brain in a vat.
>
> I don't think I am, but I am not "certain."
Well, hold on a second. I asked you before if you were criticizing
Objectivists ... you certainly seemed certain when you said you were. Are you
criticizing Objectivists?
db...@tampatrib.com
Chris Wolf <cwo...@nwlink.com> wrote:
> I decided to go and look for myself. I found a small brown object,
> floating in a pool of liquid, in a white vat labeled "Jesus."
Ha! I just want to know how it's so certain that there are "Objectivists" and
that it can "criticize" "them."
Joe Durnavich
Ironically, sometimes when people say things like "I was certain I
left my keys on the kitchen table," they say it while looking at the
kitchen table and seeing the keys really aren't there like they
thought. "Certain" was an assessment of their state of knowledge. "I
was certain I left the keys on the table a minute ago because I
distinctly remember dropping them on the table top and swearing after
seeing I dropped them in some jelly that didn't make it onto Bobbie's
sandwich." By "certain" this parent means his knowledge about the
keys fully supported his belief they were on the table and that he had
no evidence otherwise. What this parent didn't know was that Suzie
grabbed the keys just after he walked away and flushed them down the
toilet.
--
Joe Durnavich
Owl
>>The skeptic, if he knows his business, does not say, "You can never see
>>anything." The skeptic says that you never know whether a particular sort
>>of physical object exists or not. As a result, you never know whether you
>>are seeing things or merely hallucinating things. The skeptic doesn't
argue
>>that you are a brain in a vat, in actual fact. He only says that you
>>*might* be one. If, in fact, you're not one, then you see things all the
>>time (even though you don't know it).
>
>This is the representational model of perception stated in the
>skeptic's vague, indecisive, but suggestive way. Once again the
What I said above isn't exactly the representational theory. The
representational theory says that we're directly aware of mental states (or
'representations') and indirectly aware of physical things. Above, I didn't
say what, if anything, we're aware of.
>skeptic has to adopt a privileged position to know about the true
>relation between our perception and reality, namely, that our
>perceptions are mediated by a wall of possible error, delusion, and
>hallucination.
I'm not sure what you mean by a "privileged position". The skeptic is not
claiming to be any less prone to perceptual illusions and error than
everyone else.
>Consider that every single word and concept the skeptic utters, he had
>to learn through a process of observing and reasoning about the
>external world. He learned concepts like "possible," "contingent,"
>"proof," "true," "false," etc. using the very process he has so many
>doubts about. The conclusions he draws about what might or might not
>be the case are based on the same knowledge, even the ones he says are
>not contingent. For example, one must learn arithmetic by first
I don't see why you *had* to learn these concepts through observing the
external world, or through having *knowledge* of it. Wouldn't the brain in
a vat develop the same concepts?
>learning to count physical, external objects. It would be
>contradictory, then, to say that arithmetic truths are necessarily
>certain, but any knowledge based on observation is in doubt. To do so
>is to steal the concepts of numbers, addition, identity, etc.
I don't see the contradiction. In my essay "Why I am not an objectivist"
(section 3), I explained the difference between
(a) experiences causing you to form the concepts required to entertain a
proposition, and
(b) experiences justifying (giving evidence of the truth of) a proposition.
When people say knowledge of arithmetic is a priori, they mean its
*justification* does not rest on experience. There's no conflict between
this and the statement that experiences cause you to form the arithmetical
concepts. Since arithmetic is (justificatorily) a priori, it can be
certain, even though experiential knowledge is uncertain. Related point:
Even if you are a brain in a vat, you still know tha 2+2=4. Even if your
initial experiences of counting things were actually hallucinatory (so you
were only counting hallucinated things), you still know that 2+2 = 4.
>The skeptic is right in that you can't prove the direct model of
>perception because to do so leads to a circular argument. The
>skeptic, however, as would any representationalist will have to adopt
>the direct model to make their case against it. Consider the case of
>hallucinations. How did the skeptic find out about hallucinations?
>(1) He observed subjects suffering hallucinations who stated they saw,
>say, lizards running around the room when the skeptic saw that no
>lizards were in the room. Or, (2), the skeptic periodically suffers
First, I don't see why the skeptic would have to adopt a *direct* realist
view of perception, as opposed to indirect. Why couldn't the skeptic have
been *indirectly* aware that no lizards were in the room?
Second, the skeptic doesn't actually need to know whether there are lizards
in the room or not, in order to know that a hallucination exists. All he
needs to know is that there is a discrepancy between two perceptions; this
is enough to show that at least one of them is wrong, without being able to
determine which.
But then, you might point out that even to know that another person was
having a certain perception, the skeptic would have to know that the other
person existed, which is just the kind of thing he says he can't know. But
he could make a similar response to this as well. He knows that there
*appears* to be another person, who appears to be having such-and-such
experience. If this appearance is false, then the skeptic himself is
hallucinating the other person. If the appearance is true, then either the
other person is hallucinating the lizards, or the skeptic is hallucinating
the absence of lizards. So, there are three possibilities, but all involve
some hallucination or other. The skeptic doesn't know which of them is the
case, but he knows there is at least one hallucination.
>Another way to look at this is this: I just looked at my coffee cup
>and I saw that it was empty. That's about a simple and direct
>observation as they come. The skeptic says I might be wrong about
>this because of the possibility of hallucinations, BIVs, error, etc.
>His knowledge of these things are based on many, many, more
>observations than my simple single observation. How could it be that
>his sophisticated scientific discoveries of the features of perception
>are more certain than my simple observation about my coffee cup?
First, the skeptic need not claim that his belief in hallucinations is *more
certain* than your belief in the coffee cup. The skeptic might claim only
that there is *some chance* that your belief in the coffee cup is mistaken;
and for this, it is only necessary that there be some chance that his
beliefs about hallucinations are correct.
Second, a belief based on many observations actually can be more certain
than a belief based on a single observation. For instance, my belief that
there are rocks is more certain than my belief that there's a cup on my
desk, precisely because the former is supported by more observations.
>The skeptic may counter that even his ideas are in doubt, that as you
>say, hallucinations "might" be happening. Well, here's a guy who is
Right.
>in doubt about just about everything; who can't tell if he is
>hallucinating or not; whose entire base of knowledge is tainted with
>the possibility of error; and who may be cognitively isolated from
>reality. He doesn't give us much reason to listen to him, does he?
Again, the skeptic isn't trying to prove that most of your beliefs about the
external world are false. He's just saying there's a possibility of error.
Hence, he doesn't need any absolutely certain premises to stand on. And he
does give you reasons to listen to him - the reasons we have already
discussed.
>The idea of the brain in the vat also doesn't support the skeptic's
>claims about the nature of perception. The function of our perceptual
>faculties is to become aware of features in the world. What an object
>looks like to us depends on the nature of the object, and the nature
>of our senses, brain, etc. What if you were a BIV? Rather than
>perceiving objects in the world, you would be perceiving states in a
>simulator. These states in the simulator might be different voltage
>levels stored in a multitude of transistors. These voltages are every
>bit as real as trees and horses. The way these voltages states appear
>to you, with colors and shapes of trees and horses are how they are
>supposed to look given your perceptual facilities. There is no "true
>look" intrinsic to a voltage state, no one way they are supposed to
>look. If you were a BIV, you would be discriminating real features in
>the simulator and be able to derive knowledge from them by observing
>them--the very act the skeptic denies.
This is the most interesting - but most implausible - part of your message.
(This is like Putnam's response - did you read Putnam?)
There may not be any *one* way that a thing is 'supposed to' look; but there
certainly are ways that a thing cannot look. Otherwise, there would be no
such thing as a hallucination. (You don't think there's no such thing as
hallucination, do you?) For all experiences are caused by something. Even
the hallucination of the lizards that we discussed above is caused by
something--say, by abnormal chemicals in the brain. Whenever you have those
chemicals in your brain (and the rest of your brain is in the same state),
you will have that kind of experience. Therefore, you could argue, the
experience discriminates that brain state. And the brain state is perfectly
real. So it's actually not a hallucination at all; it's a perception of
reality. Just like everything else.
We don't want our response to the skeptic to prove too much. We don't want
to give a response which implies that hallucinations and illusions are
impossible; rather, we want to show how the occasional hallucination or
illusion is consistent with our gaining knowledge of the external world in
general.
o
Owl
Tom Runnacles wrote in message <3780D25F...@elec.qmw.ac.uk>...
>(1) If you were a brain in a vat on Mars, sinister Martian scientists
>could stimuluate your brain in such a way as to cause your experiences
>to be qualitatively indistinguishable from those you are having now.
>
>(2) If you were to know that you are not a brain in a vat on Mars, there
>would have to be some feature of your experience which enabled you to
>distinguish the case in which you are a brain in a vat on Mars from the
>case in which you are not.
>(3) You do not know that you are not a brain in a vat on Mars.
I think (2) is not completely clear, because I'm not sure what counts as a
'feature enabling me to distinguish X from Y'. Here's two ways to do the
argument:
1. The experiences a BIV would have would be qualitatively the same as the
experiences you actually have.
2. In order to know you are not a BIV, you must have experiences that are
qualitatively different from the experiences a BIV would have.
3. Therefore, you do not know you are not a BIV.
Or:
1. The experiences a BIV would have *could* be qualitatively the same as the
experiences you actually have.
2. In order to know you are not a BIV, you must have experiences that a BIV
could not have.
3. Therefore, you do not know you are not a BIV.
With the first version, I think (1) is false. A BIV might have any kind of
experience. With the second version, I think (2) is false. (2) results
when I interpret your idea of evidence "distinguishing X from Y" as evidence
inconsistent with either X or Y. But what if you have evidence that just
makes Y highly improbable, and makes X highly probable. Does that
"distuinguish" the two? Non-skeptics should answer yes.
Another issue, which I think is more to the heart of the matter: This idea
of having evidence to distinguish one thing from another appears to assume
an indirect realist view of perception: that all beliefs about the external
world must be based on beliefs about the qualitative character of inner
experiences.
So, if you're a direct realist, you'll reject (2). If you're an indirect
realist, then you're pretty much happy with knowledge based on probable
reasoning, so you won't care that a BIV *could* have the same experiences as
a normal person.
o
Robert F. Benz
Maybe you are a brain in a pestilent bowl of fetid stuff.
Jesus07312
>that it can "criticize" "them."
>
I never said I was certain. It seems highly likely that there are objectivists
since all of my experience suggests that there are and I have no reason to
doubt my experience.
-Jesus
Jesus07312
>
>Well, hold on a second. I asked you before if you were criticizing
>Objectivists ... you certainly seemed certain when you said you were. Are you
>criticizing Objectivists?
Yes I almost certainly am. But I am not totaly certain. When someone asks if
your mom is at home, and she told you that she'd be at home, you are allowed to
say "yes" because it is highly likely that she is as home. But, she may have
realized she needed something and went to the store.
It is simple logic that if you accept that your mind is finite, then you cannot
be completely certain about anything. I am NOT saying that you can't know
anything well enough to act on it. Consider my example with rolling a 50 sided
die 100 times. You are not certain that the sum will be over 101, but you will
act on the premise that it is. Anything else would be foolish. This is the type
of uncertainty that I am talking about, and the type that we all have. Not the
misrepresenation: "I am not certain of anything, so I can't take any action or
say or do anything."
You can however be "objectivist certain." which is what objectivists mean when
they "certain." In english this translates into "I am certain according to the
evidence that I think I have, but not nessecarily according to 'reality'"
-Jesus
db...@tampatrib.com
Jesus07312 <jesus...@aol.com> wrote:
> Yes I almost certainly am. But I am not totaly certain.
You're not totally certain you're criticizing Objectivists?
-- at no extra charge
Sent via Deja.com http://www.deja.com/
Share what you know. Learn what you don't.
Matt Ruff / Lisa Gold
>
> Matt Ruff wrote:
>
>> Gordon G. Sollars wrote:
>>
>>> I think you grant the skeptic far too much, Matt. What reason would
>>> you have for thinking that you were a brain in a vat on Mars that
>>> would be different from your thinking that you were a brain in a vat
>>> on Venus?
>>
>> None that's different. There's no positive evidence for either;
>> merely a lack of omniscience on my part that prevents from saying,
>> with absolute certainty, that neither is true.
>
> What do you mean by "absolute certainty"?
The condition of knowing that X cannot possibly be false. This requires
that (a) you know you have all relevant information and (b) you know
you've considered all possible implications arising from that
information and (c) you know you haven't made any mistakes in drawing
your conclusion.
> Do you mean the certainty that comes from a logical deduction?
> Even there a mistake can be made. So what is "absolute certainty"?
An unobtainable ideal, for the most part. Which, by the way, probably
explains people's interest in the whole "brains in vats" notion. We've
all experienced situations where something that we were *emotionally*
certain was true turned out not to be -- so it's an interesting thought
experiment to carry that to an extreme, and ask what it would mean if
*everything* we felt reasonably sure of turned out to be false.
> As a good pragmatist, I don't think that is a very interesting
> notion of certainty.
You don't think it's interesting, or you don't think it's useful? I
agree that absolute skepticism is useless as an approach to day-to-day
living, but I still enjoy reading Philip K. Dick novels.
>>> Robert Nozick considers this in /Anarchy, State, and Utopia/ when he
>>> talks about an "experience machine". Wouldn't you be troubled to
>>> learn that it had been a perfect illusion that you had written SG&E?
>>
>> But that's the whole point; if the illusion is perfect, I *can't*
>> learn it.
>
> Why does "perfect illusion" imply "perfectly sustainable illusion"?
I guess I assume that the only way to learn that an illusion is an
illusion is by finding a seam -- something about it that is *different*
from the thing it attempts to mimic, that allows it to be distinguished
from reality.
Yes, if I *learned* that my memories of having written SG&E were false,
that would be quite disturbing, and would make an immense difference in
my life. My question about "does it matter?" referred to an undetected
(and undetectable) illusion.
> You are certain that you wrote SG&E, at least as certain as you are
> of anything else.
I believe that I wrote it, and would not seriously credit
unsubstantiated suggestions to the contrary (though I'm certainly
willing to consider the possibility as a thought experiment). But if it
happened that my belief was false, but I never *learned* that it was
false, nor knowingly suffered any consequences as a result of it being
false, I'm not sure what difference it would make that it was false.
-- M. Ruff
Gordon G. Sollars
Storyt...@worldnet.att.net writes...
> Gordon G. Sollars wrote:
...
> > Do you mean the certainty that comes from a logical deduction?
> > Even there a mistake can be made. So what is "absolute certainty"?
>
> An unobtainable ideal, for the most part.
Why bother with "for the most part"? When are your three conditions ever
met?
> Which, by the way, probably
> explains people's interest in the whole "brains in vats" notion. We've
> all experienced situations where something that we were *emotionally*
> certain was true turned out not to be -- so it's an interesting thought
> experiment to carry that to an extreme, and ask what it would mean if
> *everything* we felt reasonably sure of turned out to be false.
I don't know the entire history of the "brains in vats" notion, but I
don't think that that is the motivation in philosophy.
> > As a good pragmatist, I don't think that is a very interesting
> > notion of certainty.
>
> You don't think it's interesting, or you don't think it's useful? I
> agree that absolute skepticism is useless as an approach to day-to-day
> living, but I still enjoy reading Philip K. Dick novels.
Interesting, sminteresting. I am a big fan of VALIS, too. I was
thinking in terms of philosophy, not literature (I still think that there
is a difference, Richard Rorty's recent department affiliations
notwithstanding). "Useful" if you like.
...
> > Why does "perfect illusion" imply "perfectly sustainable illusion"?
>
> I guess I assume that the only way to learn that an illusion is an
> illusion is by finding a seam -- something about it that is *different*
> from the thing it attempts to mimic, that allows it to be distinguished
> from reality.
That's fine; what I was getting at was that a "perfect illusion" does not
imply (to me) an illusion that is /never/ detected.
> Yes, if I *learned* that my memories of having written SG&E were false,
> that would be quite disturbing, and would make an immense difference in
> my life.
But how could you learn this? What conditions would have to hold? I
happen to have a copy of SG&E on the shelf behind me and I can see "Matt
Ruff" on the spine. Now, perhaps it was written by another "Matt Ruff",
or your name is not really "Matt Ruff", or the name is a pseudonym. But
these cases do not show that there is no author of SG&E who has memories
of writing it.
> > You are certain that you wrote SG&E, at least as certain as you are
> > of anything else.
>
> I believe that I wrote it, and would not seriously credit
> unsubstantiated suggestions to the contrary (though I'm certainly
> willing to consider the possibility as a thought experiment).
What sort of "substantiation" could there be? What evidence is there
that you wouldn't have more reason to believe was faked than your memory?
> But if it
> happened that my belief was false, but I never *learned* that it was
> false, nor knowingly suffered any consequences as a result of it being
> false, I'm not sure what difference it would make that it was false.
Would it make no difference to you if your spouse had affairs (assuming
you have agreed to remain faithful to each other), as long as you never
learned about them?
--
Gordon Sollars
gsol...@virginia.edu
Jesus07312
>left my keys on the kitchen table," they say it while looking at the
>kitchen table and seeing the keys really aren't there like they
>thought. "Certain" was an assessment of their state of knowledge.
But they DID leave the keys on the table, they just aren't there now. They say
they certainly left them on the table and mean "Reality is not any other way."
They do not mean "I left my keys here, but further evidence might reveal that I
actualy threw them out the window." If they have any doubts whether or not they
left their keys there, they'd say "I think I left them there" or something
similar. They are actualy certain that they left their keys on the table. They
are not certain that no one else took them, and they would not claim that "I am
certain that my keys will be on the table when i go look for them there"
because they are not certain of this. The only thing they claim certainty of
was putting the keys on the table, which they did. When they say this, they
mean that further evidence will never be found to suggest that they actualy did
something else with their keys, which is not the objectivist definition.
-Jesus
Jesus07312
Correct. And you are not totaly certain that you're asking me that.
-Jesus
Joe Durnavich
>>Consider that every single word and concept the skeptic utters, he had
>>to learn through a process of observing and reasoning about the
>>external world. He learned concepts like "possible," "contingent,"
>>"proof," "true," "false," etc. using the very process he has so many
>>doubts about. The conclusions he draws about what might or might not
>>be the case are based on the same knowledge, even the ones he says are
>>not contingent. For example, one must learn arithmetic by first
>
>
>I don't see why you *had* to learn these concepts through observing the
>external world, or through having *knowledge* of it. Wouldn't the brain in
>a vat develop the same concepts?
Well, the brain in the vat is observing the external world, namely,
the various states of a simulator. My point is that we can introspect
and look back at how we came to know what we know. We can see a
pattern where at one point in our lives we did not understand a
particular concept and at a later point we did understand it. We can
also see that a process of observing and reasoning about the world
lead to that understanding. The skeptic can ask himself why he uses
the English language as opposed to, say, French. Was he able to make
up the language himself, or did it come from his environment?
Now don't get me wrong, some concepts, such as "memory" are not
learned solely from the environment. You had to introspect to learn
that. But before you could have memories, you had to observe
something first to have memories about.
I like the Objectivist position that we start out life "tabula rasa"
with no knowledge and then we acquire knowledge step by step through a
process of observation and reason. I am usually, uh, skeptical of
philosophical assertions that overlook or accidently deny these roots
of our knowledge.
>>learning to count physical, external objects. It would be
>>contradictory, then, to say that arithmetic truths are necessarily
>>certain, but any knowledge based on observation is in doubt. To do so
>>is to steal the concepts of numbers, addition, identity, etc.
>
>
>I don't see the contradiction. In my essay "Why I am not an objectivist"
>(section 3), I explained the difference between
>(a) experiences causing you to form the concepts required to entertain a
>proposition, and
>(b) experiences justifying (giving evidence of the truth of) a proposition.
>
>When people say knowledge of arithmetic is a priori, they mean its
>*justification* does not rest on experience. There's no conflict between
>this and the statement that experiences cause you to form the arithmetical
>concepts. Since arithmetic is (justificatorily) a priori, it can be
>certain, even though experiential knowledge is uncertain. Related point:
>Even if you are a brain in a vat, you still know tha 2+2=4. Even if your
>initial experiences of counting things were actually hallucinatory (so you
>were only counting hallucinated things), you still know that 2+2 = 4.
You need to step back a little more, expand your scope, and identify
exactly how it was you came to know how to count and add. If we
locked a newborn infant in a sensory depravation tank and fed him
intravenously for, say, 15 years, do you think he would know that 2 +
2 = 4 when we took him out? Are hallucinations consistent enough to
learn arithmetic from?
In your paper, you say that universals such as "whiteness" really
exist in some fashion and that a priori knowledge is based on
reasoning about universals. Don't universals like "1" (or "unit"),
"identical," "sequence," and "addition," also have a basis in the
world?
Consider what it takes to teach kids math. Say you wanted to teach
someone the concept "color" and you showed them a several red books
and said, "See these are all the color red." At this point the person
might not be able to focus on the right aspect of the books to know
what part of it was "red." The person might think "red" was the book.
(It wasn't until I was an adult that I understood what the accent on
syllables meant. In school, teachers repeated words over and over to
me with accents on different syllables, but I never picked up on which
sound was the accent.) With counting, children are taught to count a
variety of groups of different objects so that they can grasp that the
"oneness," and "twoness" are a particular aspect of a group of
objects. Quite a few crayon drawings probably are stuck to
refrigerators around the world showing one cherry with the numeral "1"
next to it, two trees with the number "2", etc.
This drilling goes on for years before we get comfortable with the
methods of arithmetic. I knew seniors in high school who had to take
math classes that focused on adding, subtracting, etc.
I'll grant you that once you understand math, you don't need to appeal
to that understanding to justify it in normal life. "2 + 2 = 4" is
adequately justified by appeal to the axioms and rules of arithmetic.
But that justification is necessarily built on a grounding of our
understanding which was derived through a rigorous observation of the
world. In philosophy, we step back a bit and justify the axioms.
Sometimes this justification is merely identifying where the axioms
fit in our hierarchy of knowledge including what depends on them as
fundamentals, and what they depend on for understanding. This is a
different style of justification than you talk about in your paper.
It's really more a matter of getting us back in touch with the roots
of our knowledge.
>>The skeptic is right in that you can't prove the direct model of
>>perception because to do so leads to a circular argument. The
>>skeptic, however, as would any representationalist will have to adopt
>>the direct model to make their case against it. Consider the case of
>>hallucinations. How did the skeptic find out about hallucinations?
>>(1) He observed subjects suffering hallucinations who stated they saw,
>>say, lizards running around the room when the skeptic saw that no
>>lizards were in the room. Or, (2), the skeptic periodically suffers
>
>
>First, I don't see why the skeptic would have to adopt a *direct* realist
>view of perception, as opposed to indirect. Why couldn't the skeptic have
>been *indirectly* aware that no lizards were in the room?
Ok, let's save my argument above for the representationalist. My
point is that the skeptic has to form the concept hallucination on the
basis of perceptions of real things.
>Second, the skeptic doesn't actually need to know whether there are lizards
>in the room or not, in order to know that a hallucination exists. All he
>needs to know is that there is a discrepancy between two perceptions; this
>is enough to show that at least one of them is wrong, without being able to
>determine which.
>
>But then, you might point out that even to know that another person was
>having a certain perception, the skeptic would have to know that the other
>person existed, which is just the kind of thing he says he can't know. But
>he could make a similar response to this as well. He knows that there
>*appears* to be another person, who appears to be having such-and-such
>experience. If this appearance is false, then the skeptic himself is
>hallucinating the other person. If the appearance is true, then either the
>other person is hallucinating the lizards, or the skeptic is hallucinating
>the absence of lizards. So, there are three possibilities, but all involve
>some hallucination or other. The skeptic doesn't know which of them is the
>case, but he knows there is at least one hallucination.
Let's look at your 3 cases:
(1) If this appearance is false, then the skeptic himself is
hallucinating the other person.
In other words, if the skeptic is hallucinating the other person, then
he is hallucinating the other person.
(2) If the appearance is true, then either the other person is
hallucinating the lizards,
In other words, the skeptic sees and knows about the hallucinating
person.
(3) or the skeptic is hallucinating the absence of lizards.
In other words, the other person really sees and knows about the
lizard, and the skeptic really sees and knows about the other person.
Case (1) is circular if you don't offer a reason to prefer it over the
other cases. In cases (2) and (3), the skeptic formed the concept of
"hallucination" in the context of normal direct perception, which was
the point I was trying to make.
As for your argument above, you have fallen back to the
representational model, which you promised you wouldn't do. That
model is premised on the notion that all we are aware of are
"appearances." You can't learn what an "appearance" is without first
observing and identifying something, say, a tree, and then
introspecting and identifying that the tree "appears" to you. When we
put on our philosophy hats, we take concepts like "appearance" for
granted and forget how we came to know what it is. We forget that we
first become aware of objects in the world and only then did we later
identify that the objects "appear" to us. Knowing about objects is
fundamental to knowing about appearances of those objects.
>>The idea of the brain in the vat also doesn't support the skeptic's
>>claims about the nature of perception. The function of our perceptual
>>faculties is to become aware of features in the world. What an object
>>looks like to us depends on the nature of the object, and the nature
>>of our senses, brain, etc. What if you were a BIV? Rather than
>>perceiving objects in the world, you would be perceiving states in a
>>simulator. These states in the simulator might be different voltage
>>levels stored in a multitude of transistors. These voltages are every
>>bit as real as trees and horses. The way these voltages states appear
>>to you, with colors and shapes of trees and horses are how they are
>>supposed to look given your perceptual facilities. There is no "true
>>look" intrinsic to a voltage state, no one way they are supposed to
>>look. If you were a BIV, you would be discriminating real features in
>>the simulator and be able to derive knowledge from them by observing
>>them--the very act the skeptic denies.
>
>
>This is the most interesting - but most implausible - part of your message.
>(This is like Putnam's response - did you read Putnam?)
In fairness to me, I was talking about the brain-in-vat scenario and
not hallucinations. My point was that the BIV scenario is not
evidence for the skeptic because in that scenario, the brain is
learning about aspects of the world through observation. In other
words, it is not an example of consciousness creating it own contents.
>There may not be any *one* way that a thing is 'supposed to' look; but there
>certainly are ways that a thing cannot look. Otherwise, there would be no
>such thing as a hallucination. (You don't think there's no such thing as
>hallucination, do you?) For all experiences are caused by something. Even
>the hallucination of the lizards that we discussed above is caused by
>something--say, by abnormal chemicals in the brain. Whenever you have those
>chemicals in your brain (and the rest of your brain is in the same state),
>you will have that kind of experience. Therefore, you could argue, the
>experience discriminates that brain state. And the brain state is perfectly
>real. So it's actually not a hallucination at all; it's a perception of
>reality. Just like everything else.
The skeptic actually needs to offer us more proof about
hallucinations. We really are taking a lot of it for granted. We
take it for granted that a hallucinated object is indistinguishable
from a perceived real object. We base this on mental patients or acid
trippers who say they see objects that aren't there. But in both
cases, the brain is not functioning properly and we don't know for
sure if the image of the hallucination is really clear and distinct or
the hallucinator just misjudges them to be that way. We take it for
granted that the brain malfunction or drugs did not also impair
judgment. The pink elephants that an alcoholic sees may be just
indistinct pink flashes of light after all.
Also, is it the nature of hallucinations to be clear and distinct for
extended periods of time? Are there any cases in the medical
literature where patients have hallucinated, say, an entire semester
of freshman chemistry?
>We don't want our response to the skeptic to prove too much. We don't want
>to give a response which implies that hallucinations and illusions are
>impossible; rather, we want to show how the occasional hallucination or
>illusion is consistent with our gaining knowledge of the external world in
>general.
I agree that hallucination and illusions are real and possible. I
came to know about hallucinations and illusions the same way I came to
know about trees, rocks, coffee cups, and skeptics: by observing the
world around me.
The skeptic should at least take satisfaction in the fact that I am
skeptical of his claims...
--
Joe Durnavich
Tony Shrapnel
> Oh, here's another thing about the argument:
>
> Tom Runnacles wrote in message <3780D25F...@elec.qmw.ac.uk>...
>
> >(1) If you were a brain in a vat on Mars, sinister Martian scientists
> >could stimuluate your brain in such a way as to cause your experiences
> >to be qualitatively indistinguishable from those you are having now.
> >
> >(2) If you were to know that you are not a brain in a vat on Mars, there
> >would have to be some feature of your experience which enabled you to
> >distinguish the case in which you are a brain in a vat on Mars from the
> >case in which you are not.
>
> >(3) You do not know that you are not a brain in a vat on Mars.
>
> I think (2) is not completely clear, because I'm not sure what counts as a
> 'feature enabling me to distinguish X from Y'. Here's two ways to do the
> argument:
>
> 1. The experiences a BIV would have would be qualitatively the same as the
> experiences you actually have.
> 2. In order to know you are not a BIV, you must have experiences that are
> qualitatively different from the experiences a BIV would have.
Rather than address this as an empirical knowledge issue, would it be valid
to address it as an a priori knowledge issue? Drawing upon your own
writings, "empirical knowledge" is either known or justified by
observations; whereas a priori knowledge is "an item of knowledge which is
not an observation and which is not justified by observations".
I claim to "know" that I am not a brain-in-a-vat, as I have not a shred of
empirical knowledge to suggest that I am and (more importantly) within the
constraints of the proposition, I have no prospect of ever resolving the
issue impirically. However, my knowledge is real (I do actually "know" that
I am not a BIV. I know that as fully as I know that 1+1=2). But as this
knowledge is (ie. seems to be) unprovable empirically, can't it still be
fully "known" in the a priori sense? Or, if not, then under what
philosophical regime do I know it (because I do *know* it - and so do you).
Tony Shrapnel
Tony Shrapnel
news:37889ce5....@news.supernews.com...
> Tony Shrapnel writes:
>
> >Chris Wolf <cwo...@nwlink.com> wrote in message
> >news:3782c18e....@news.supernews.com...
> >> Steven Smolinski writes:
> >>
> >> >So to your first premise, that I may be a brain in a vat, I say: I
won't
> >> >even consider past that point until some credible evidence points in
that
> >> >direction.
>
> >> My vat needs changing.
>
> >How do you know?
>
> Some of Jim Klein's posts started to sound reasonable.
Ah! So he has just had an oil change, and now you want one too.
TS
Tony Shrapnel
news:3781EC...@worldnet.att.net...
> Tom Runnacles wrote:
> >
> > Objectivists seem very confident that scepticism about the external
[snip]
> Well, all else being equal, it seems much simpler to assume that I am
> *not* a brain in a vat on Mars -- Occam's razor, y'know. Also, so long
> as the illusion is perfect, does it *matter* that it's an illusion?
If the illusion is perfect, then God is a wicked Martian scientist.
TS
Owl
>>I don't see why you *had* to learn these concepts through observing the
>>external world, or through having *knowledge* of it. Wouldn't the brain
in
>>a vat develop the same concepts?
>
>Well, the brain in the vat is observing the external world, namely,
>the various states of a simulator. My point is that we can
As you know, I disagree that the BIV is observing anything. I think it's
just hallucinating.
>>Even if you are a brain in a vat, you still know tha 2+2=4. Even if your
>>initial experiences of counting things were actually hallucinatory (so you
>>were only counting hallucinated things), you still know that 2+2 = 4.
>
>You need to step back a little more, expand your scope, and identify
>exactly how it was you came to know how to count and add. If we
>locked a newborn infant in a sensory depravation tank and fed him
>intravenously for, say, 15 years, do you think he would know that 2 +
>2 = 4 when we took him out? Are hallucinations consistent enough to
>learn arithmetic from?
No, you have to have the right sort of hallucinations - like those of the
brain in a vat. In other words, if a person had his brain stimulated
electrically (over a period of several years) in the same way as brains are
usually stimulated, but there weren't any physical objects that he was
perceiving (so they were hallucinations), then that person would form the
same concepts as a normal person.
If true, what this shows is that forming concepts does not require
*perceiving* reality. It requires having experiences *as of* perceiving -
that is, experiences subjectively like perceiving.
As I understand it, your whole response to the skeptic is to say that he,
the skeptic, could not have formed the concepts used in his skeptical
arguments, unless he had perceived the real world at some time. But the
skeptic will counter that he could have formed those concepts if he were a
brain in a vat, having never perceived the real world but instead only
hallucinated -- provided that the hallucinations had been qualitatively just
like perceptions.
Now, as far as I understand it, your only response to this move is to claim
that a brain in a vat actually is accurately perceiving reality.
>In your paper, you say that universals such as "whiteness" really
>exist in some fashion and that a priori knowledge is based on
>reasoning about universals. Don't universals like "1" (or "unit"),
>"identical," "sequence," and "addition," also have a basis in the
>world?
I'm not sure what you mean by "have a basis", but I do think that universals
such as unity, identity, sequence, and addition exist. I also think there
are concrete objects instantiating them. (E.g., there is a watch on my
desk, which instantiates [unity], relative to the category [watch].)
I also agree with you (since I'm not a skeptic) that the way we actually
learned arithmetical concepts was by perceiving things in the world, which
we knew about. But the skeptic will say that the brain in the vat could
have had those same experiences as of perceiving things, and would thereupon
have formed the same arithmetical concepts. And I don't see why this
wouldn't be the case.
By the way, numbers are a particularly interesting kind of universal. Most
of the universals are instantiated by concrete particulars - they are
properties of particulars or relations between particulars. But a number,
in my view, is a relation between a concrete particular (a particular
aggregate) and a type or category (the latter being itself a universal).
That's why I say that my watch instantiates [1] *relative to* the category
[watch]. But relative to, say, the category [molecule], it instantiates
some much larger number, something like 10^23.
>Let's look at your 3 cases:
>
>(1) If this appearance is false, then the skeptic himself is
>hallucinating the other person.
>In other words, if the skeptic is hallucinating the other person, then
>he is hallucinating the other person.
My first case was: if there isn't another person here, then the skeptic is
hallucinating (because he seems to see another person).
>(2) If the appearance is true, then either the other person is
>hallucinating the lizards,
>In other words, the skeptic sees and knows about the hallucinating
>person.
My second case was that there is another person here, but there are no
lizards. In this case, the other person is hallucinating. Nothing follows
about "knowledge". How did you ocnclude that the skeptic "knows" about the
hallucinating person? Remember, just because case (2) holds, wouldn't mean
the skeptic knew case 2 held. The skeptic still doesn't know whether it's
case 1, 2, or 3.
>(3) or the skeptic is hallucinating the absence of lizards.
>
>In other words, the other person really sees and knows about the
>lizard, and the skeptic really sees and knows about the other person.
The third case was that the lizards are there, so the skeptic is
hallucinating their absence. Again, nothing follows about knowledge. The
other person still doesn't *know* that case 3 holds.
>As for your argument above, you have fallen back to the
>representational model, which you promised you wouldn't do. That
>model is premised on the notion that all we are aware of are
>"appearances." You can't learn what an "appearance" is without first
>observing and identifying something, say, a tree, and then
>introspecting and identifying that the tree "appears" to you.
I think I've said enough above to make clear what the skeptic's response to
this would be - he would say you could form the concept 'appearance' by
having experiences *as of* observing real things (experiences which you took
to be genuine perceptions).
>In fairness to me, I was talking about the brain-in-vat scenario and
>not hallucinations. My point was that the BIV scenario is not
>evidence for the skeptic because in that scenario, the brain is
>learning about aspects of the world through observation. In other
>words, it is not an example of consciousness creating it own contents.
Well, all experiences are physically caused by something, whether the
experiences are hallucinatory or not. It seems pretty clear that the BIV
scenario IS a hallucination scenario. Are you saying it isn't, just because
the BIV's experiences are caused by something physical?
>The skeptic actually needs to offer us more proof about
>hallucinations. We really are taking a lot of it for granted. We
>take it for granted that a hallucinated object is indistinguishable
>from a perceived real object. We base this on mental patients or acid
>trippers who say they see objects that aren't there. But in both
>cases, the brain is not functioning properly and we don't know for
>sure if the image of the hallucination is really clear and distinct or
>the hallucinator just misjudges them to be that way. We take it for
This is true, and in fact I do not think hallucinations are generally
indistinguishable from perceptions. But that's just because I don't think
there are any brains in vats anywhere. If the BIV scenario were realized,
the hallucinations *would* be indistinguishable from normal perceptions.
>The skeptic should at least take satisfaction in the fact that I am
>skeptical of his claims...
Yeah. The purest skeptic would be skeptical of skepticism too.
o
Owl
>I claim to "know" that I am not a brain-in-a-vat, as I have not a shred of
>empirical knowledge to suggest that I am and (more importantly) within the
>constraints of the proposition, I have no prospect of ever resolving the
>issue impirically.
This doesn't sound very convincing. Couldn't the skeptic say, "Well, you
have not a shred of empirical knowledge to suggest that you're NOT, and you
have no prospect of ever resolving the issue empirically. So why not
conclude that you know you ARE a brain in a vat?" Wouldn't this be parallel
reasoning?
> However, my knowledge is real (I do actually "know" that
>I am not a BIV. I know that as fully as I know that 1+1=2). But as this
>knowledge is (ie. seems to be) unprovable empirically, can't it still be
>fully "known" in the a priori sense? Or, if not, then under what
>philosophical regime do I know it (because I do *know* it - and so do you).
That's a good question. If it were a priori knowledge, it would be an
exception to my general rule that a priori knowledge is knowledge of the
properties of and relations between universals. It would also be a case of
contingent, a priori knowledge.
I actually think it's empirical knowledge. Since I'm a direct realist, I
think you know observationally (foundationally) that you have a pair of
hands, legs, and so on. You can know this by looking at them, or feeling
them. It follows from this that you're not a brain in a vat.
Indirect realists would also take the knowledge to be empirical. They would
probably say that the best explanation of our experiences is that there are
physical objects causing them. The BIV scenario is a *possible*
explanation, they would say, but an inferior one.
o
Tony Shrapnel
> Tony Shrapnel wrote in message ...
>
> >I claim to "know" that I am not a brain-in-a-vat, as I have not a shred
of
> >empirical knowledge to suggest that I am and (more importantly) within
the
> >constraints of the proposition, I have no prospect of ever resolving the
> >issue impirically.
>
> This doesn't sound very convincing. Couldn't the skeptic say, "Well, you
> have not a shred of empirical knowledge to suggest that you're NOT, and
you
> have no prospect of ever resolving the issue empirically. So why not
> conclude that you know you ARE a brain in a vat?" Wouldn't this be
parallel
> reasoning?
Point taken.
> > However, my knowledge is real (I do actually "know" that
> >I am not a BIV. I know that as fully as I know that 1+1=2). But as this
> >knowledge is (ie. seems to be) unprovable empirically, can't it still be
> >fully "known" in the a priori sense? Or, if not, then under what
> >philosophical regime do I know it (because I do *know* it - and so do
you).
>
> That's a good question. If it were a priori knowledge, it would be an
> exception to my general rule that a priori knowledge is knowledge of the
> properties of and relations between universals. It would also be a case
of
> contingent, a priori knowledge.
Hmm. But the class of knowledge we are talking about is quite fundamental (I
think, therefore I am - an autonomous agent), so perhaps an exception is
warranted here.
> I actually think it's empirical knowledge. Since I'm a direct realist, I
> think you know observationally (foundationally) that you have a pair of
> hands, legs, and so on. You can know this by looking at them, or feeling
> them. It follows from this that you're not a brain in a vat.
But isn't the initial proposition "closed" in the sense that any experience
could be illusory? If disproving the proposition is really as simple as
looking at your foot, then I have misunderstood. This is nought but common
sense, which I thought didn't count when addressing this type of issue.
> Indirect realists would also take the knowledge to be empirical. They
would
> probably say that the best explanation of our experiences is that there
are
> physical objects causing them. The BIV scenario is a *possible*
> explanation, they would say, but an inferior one.
More common sense. I'm somewhat relieved.
Regards
Tony Shrapnel
Owl
>Hmm. But the class of knowledge we are talking about is quite fundamental
(I
>think, therefore I am - an autonomous agent), so perhaps an exception is
>warranted here.
"I think, therefore I am" is also empirical, by the way. You know you think
by introspectively observing your thinking.
>> I actually think it's empirical knowledge. Since I'm a direct realist, I
>> think you know observationally (foundationally) that you have a pair of
>> hands, legs, and so on. You can know this by looking at them, or feeling
>> them. It follows from this that you're not a brain in a vat.
>
>But isn't the initial proposition "closed" in the sense that any experience
>could be illusory? If disproving the proposition is really as simple as
>looking at your foot, then I have misunderstood. This is nought but common
>sense, which I thought didn't count when addressing this type of issue.
Skeptics, of course, don't count common sense. But I'm not a skeptic, so I
do.
The skeptic will claim that my argument is circular, since I'm assuming that
my sensory experiences are not illusory; and in order to know that, I'd have
to first know I'm not a BIV. But I'll say that the skeptic assumes he's
talking to an indirect realist. If direct realism is true, then I am not
assuming any proposition about experiences (awareness of physical objects
comes first; awareness of 'experiences' comes later). In fact, it may be
'experiences' that are the theoretical posit, not physical objects.
Anyway, I recognize that this requires more extended discussion. I have
written about it at some length, but I'm not going to do so here. Among
other things, I would have to respond to the traditional objections to
direct realism.
>> Indirect realists would also take the knowledge to be empirical. They
>would
>> probably say that the best explanation of our experiences is that there
>are
>> physical objects causing them. The BIV scenario is a *possible*
>> explanation, they would say, but an inferior one.
>
>More common sense. I'm somewhat relieved.
This, by the way, is another thing that could use more extended discussion.
Why is the BIV an inferior explanation? (One possible reason is that the
BIV hypothesis is consistent with any logically possible sequence of
experiences, but the real-world hypothesis is not. Hence, the BIV has no
explanatory or predictive value.)
o
Stephen Grossman
<th...@elec.qmw.ac.uk> wrote:
> Objectivists seem very confident that scepticism about the external
> world can be conclusively refuted.
theres no evidence to refute. You know reality regardless of your personal
motives to evade.
> (1) If you were a brain in a vat on Mars,
if you were rational, what would you say?
> Any comments?
its clear why Rand said rationalist floating abstractions were a miasma.
________________________________________________
Reason is man's basic means of survival. AYN RAND
This here thing comes from this here seed. ARISTOTLE
I reckon so! JOANN SVENDSEN
------------------------------------------------------
Tracking Marxist dialectical revolution: ZigZag
Radically systematic radical metaphysics: Existence 2
http://home.att.net/~sdgross
-------------------------------------------------------
Stephen Grossman Fairhaven, MA, USA sdg...@att.net
Stephen Grossman
<jesus...@aol.com> wrote:
> Tom, objectivists "refute" this by changing the definitions of common words,
> not by any thought process.
Tell us how you change definitions w/o a process of thought. Do you
tighten your muscles?
> They define "truth" only within a certain context of knowledge.
whereas your truth is beyond knowledge
>
> To most people I think, "truth" is almost synonnymous with reality. To
> objectivists "truth" is dependant on whatever information that you have.
> Thus,
> someone could make a statement that was not in accord with reality, and by
> objectivist standards, it would be considered "true" if it seemed quite l
> ikely
> from the evidence at hand, regardless of reality.
Rand rejects subjectivism and pseudo-objectivism (intrinsicism) by
claiming that truth is the mental recognition of reality.
Stephen Grossman
Betsy Speicher <be...@speicher.com> wrote:
> I don't have any reason to believe that I'm a brain in a vat. Do YOU think
> that YOU might be a brain in a vat, Tom? What makes you think so?
his skepticism
db...@tampatrib.com
Jesus07312 <jesus...@aol.com> wrote:
> >You're not totally certain you're criticizing Objectivists?
>
> Correct.
Well, there's not really much point in addressing your criticisms when you're
not even certain you're making them.
Joseph J. Durnavich
>As I understand it, your whole response to the skeptic is to say that he,
>the skeptic, could not have formed the concepts used in his skeptical
>arguments, unless he had perceived the real world at some time. But the
>skeptic will counter that he could have formed those concepts if he were a
>brain in a vat, having never perceived the real world but instead only
>hallucinated -- provided that the hallucinations had been qualitatively just
>like perceptions.
Let's say you asked me to prove the validity of my senses, and I
said, "There is a cup on the table and I see the cup, therefore
my senses are valid." You would ask, "How do you know the cup
is there?" And I would answer, "Because I see it." You would
be all over me in a heartbeat complaining about my circular
argument.
Now let's say you ask the skeptic to prove that a brain could
be hooked to a simulator and fooled. He would have to tell
you something about how brains and simulators worked. If you
asked him how he knows brains and simulators are that way,
he may say he's seen and studied brains and simulators. If
you object that his argument is premised on real knowledge of
the world, he may counter that he could be a brain in a vat
learning that knowledge from a simulator. Yet, you let this
circular argument slide.
Any attempt to prove (or disprove) the fundamental nature
of perception, that is the relation between the world and us
will lead to a circular argument (or a self-denying one)
because the function of proof is to reason from the evidence
of the senses.
What philosophy can offer us, is to remind us that any
assertion whatsoever will also implicity assert that
the senses are valid, that is, they are a means to
knowledge. It can remind us that first we became aware of
the world and only then could we and did we reflect on how we
became aware of it.
So, the way I deal with the skeptic is to ask "How did *you*
find that out?"
>Now, as far as I understand it, your only response to this move is to claim
>that a brain in a vat actually is accurately perceiving reality.
Yes, the states in the simulator would be real and they are something
we (and the brain) would have knowledge of. This was a smaller
part of my more general case.
Perhaps the best way to make my point clear is to do something
the skeptic will never do: take the brain in vat scenario seriously.
Say I said the BIV scenario wouldn't work because if you hooked
someone up to an old AM radio, it would never be like what we
perceive now. You would object because you have particular
ideas on how the BIV must be and just any old setup will not
work.
I'll hire a team of neurosurgeons, computer engineers, and
programmers. Your job is work with them and determine exactly
how do go about building this brain in vat simulator. When you
guys are ready, we'll get a newborn infant and you can hook him up.
You have to discover how to keep him alive long enough to
sever each and every nerve in his body, not just the senses,
but the motor neurons too because he will want to walk around
his world. Then you have to connect each nerve end to specially
designed interfaces to the computer. You will have needed to
learn the exact communications protocol are nerves, senses, and
brains use. You will have had to develop a computer system
that can simulate a significant portion of the planet Earth
and its inhabitants. You will have had to identify all this
information, store it in databases, and be able to render it
all in real time. You will have had to learn about all the
nutrients needed to keep the brain alive, plus a system to
release the right hormones such as adrenaline to cause the
brain the have the right emotions for the different
circumstances it may encounter.
Just look at all the knowledge the brain in vat scenario is
dependent on. To pull it off would be one of the greatest
intellectual achievments in all of human science.
This doesn't exactly warrant an epistemological crisis, does it?
So, it's not so much the case the the BIV is in fact
perceiving reality, but more so that the skeptic's BIV
argument can only be made on the basis of an immense
amount of scientific knowledge all arrived at by
perceiving reality. I'm saying it's crazy to be skeptical
about your knowledge *because* you know about BIVs.
>>>Even if you are a brain in a vat, you still know tha 2+2=4. Even if your
>>>initial experiences of counting things were actually hallucinatory (so you
>>>were only counting hallucinated things), you still know that 2+2 = 4.
>>
>>You need to step back a little more, expand your scope, and identify
>>exactly how it was you came to know how to count and add. If we
>>locked a newborn infant in a sensory depravation tank and fed him
>>intravenously for, say, 15 years, do you think he would know that 2 +
>>2 = 4 when we took him out? Are hallucinations consistent enough to
>>learn arithmetic from?
>
>
>No, you have to have the right sort of hallucinations - like those of the
>brain in a vat. In other words, if a person had his brain stimulated
>electrically (over a period of several years) icould be stimulated this wa
>y to conclude that you might be a brain
in a vat.
Yes, if you guys programmed enough of the right features in the
simulator, with teachers, and objects to count, etc., you could
teach the brain arithmetic. And if its simulated world had mountains
rivers, and plains, and volcanoes, and tectonic plates, you could
teach it about geology. But none of this means that *our* knowledge
is or might be false. Just think about all the knowledge you had
to learn from the world to program into the simulator. It's
not like you guys could just show the brain Adam Sandler movies over
and over and expect it to grow intellectually.
>If true, what this shows is that forming concepts does not require
>*perceiving* reality. It requires having experiences *as of* perceiving -
>that is, experiences subjectively like perceiving.
Again, I'll point out that just suggesting the BIV is possible
entails having quite a bit of knowledge about the world that you
acquired through perception. Ask yourself how *you* found out you
had senses and then ask how you found out methods to fool them.
I bet quite a few perceptions lead to that knowledge. Just how
could one discover one's eyes and what they do if one did not
look at real objects first? To identify where *your* eyes are
in the perceptual chain, you first look at, say, a tree, you
identify "there is a tree," then you introspect and identify
you are aware of the tree, and then you open and close your
eyes and see the tree come and go and identify it is your
eyes that allow you to see the tree. Notice that existence,
the tree, comes first. This is what O'ists mean by the
"Primacy of Existence" vs. the "Primacy of Consciousness."
Once *you* learned about trees and your eyes, then you learned about
brains, vats, and computers and how they may fool your eyes. But
this latter fact is dependent on the former ones. You can't
conclude that because you have seen trees, brains, vats, and
computers with your eyes that the trees, brains, and vats may
not be real.
>>Let's look at your 3 cases:
>>
>>(1) If this appearance is false, then the skeptic himself is
>>hallucinating the other person.
>
>>In other words, if the skeptic is hallucinating the other person, then
>>he is hallucinating the other person.
>
>
>My first case was: if there isn't another person here, then the skeptic is
>hallucinating (because he seems to see another person).
>
>>(2) If the appearance is true, then either the other person is
>>hallucinating the lizards,
>
>>In other words, the skeptic sees and knows about the hallucinating
>>person.
>
>
>My second case was that there is another person here, but there are no
>lizards. In this case, the other person is hallucinating. Nothing follows
>about "knowledge". How did you ocnclude that the skeptic "knows" about the
>hallucinating person? Remember, just because case (2) holds, wouldn't mean
>the skeptic knew case 2 held. The skeptic still doesn't know whether it's
>case 1, 2, or 3.
>
>>(3) or the skeptic is hallucinating the absence of lizards.
>>
>>In other words, the other person really sees and knows about the
>>lizard, and the skeptic really sees and knows about the other person.
>
>
>The third case was that the lizards are there, so the skeptic is
>hallucinating their absence. Again, nothing follows about knowledge. The
>other person still doesn't *know* that case 3 holds.
If the skeptic doesn't know which case holds, then this argument
is circular. I want to know how he came to know about hallucinations;
that they are appearances of things not really there; and that they
are possible. Your premise, that the appearance is either false or
true, implies that the skeptic already knew about hallucinations,
that is, he knew his perceptions are appearances of things that are
there or not there. All I am asking is, how did he find this out?
>>In fairness to me, I was talking about the brain-in-vat scenario and
>>not hallucinations. My point was that the BIV scenario is not
>>evidence for the skeptic because in that scenario, the brain is
>>learning about aspects of the world through observation. In other
>>words, it is not an example of consciousness creating it own contents.
>
>
>Well, all experiences are physically caused by something, whether the
>experiences are hallucinatory or not. It seems pretty clear that the BIV
>scenario IS a hallucination scenario. Are you saying it isn't, just because
>the BIV's experiences are caused by something physical?
I'm distinguishing the BIV from the hallucination because the
hallucination is usually associated with a malfunction and
it doesn't seem like one could hallucinate a whole lifetime
off of some misfiring neural circuitry. You are aware that
a newborn's brain needs frequent stimulation from the senses
in order to grow the circuitry necessary to see, hear, etc. later.
I've read of newborn cats shown only horizontal lines for the
first weeks after birth who could never see vertical lines
later (they would often run into chair legs).
You are right in that what the BIV perceives is not real, in
a sense, yet the states it perceives are real. And as you
might suspect by now, if we are going to say we know
about BIVs and simulator states, I think we have adequately
demonstrated real knowledge about the world is possible.
--
Joe Durnavich
Jesus07312
see much evidence for such a thing.
Of course things like "1+1=2" seem so obvious to us now because we have seen
them to be true constatly from our earliest memories. I think you are reading
too much into how familiar you are with this concept.
Are you saying that if a human baby were transported into an alternate reality
where 1+1= 1/2, and 1-1 =4 (so you would reduce matter by adding to it, and
expand matter by taking away from it) that the human mind by its nature would
always have a conflict with that, and never feel natural with it because humans
are bestowed with some magical "a priori" knowledge that 1+1=2?
I think that if your parents began drilling this 1+1=1/2 stuff into your head
since you were born, and also your teachers, and you saw it everyday around
you, it would feel just as natural as 1+1=2.
I cannot see any justification for claiming "a priori" knowledge. What you call
"a priori" just seems to be fundamental properties of reality that of course we
cannot immagine any other way, because we live in this reality. But is that any
reason to say they are pre-packaged in our minds?
-Jesus
Jesus07312
>Well, there's not really much point in addressing your criticisms when you're
>not even certain you're making them.
Why not? If I am 99.999999999% certain that I am, what possible harm could come
from not adressing them? I am not going to suddenly decide that I am a piece of
lettuce and be unable to continue the discussion.
You seem to have trouble understanding that because you are not *certain* of
something, it does not mean that you do not very strongly think that that
something is the case, and always act on that premise.
-Jesus
Owl
>Now let's say you ask the skeptic to prove that a brain could
>be hooked to a simulator and fooled. He would have to tell
>you something about how brains and simulators worked. If you
>asked him how he knows brains and simulators are that way,
>he may say he's seen and studied brains and simulators. If
As I tried to explain earlier, this is certainly not what the skeptic would
say. Instead, the skeptic would cheerfully admit, "You're right - maybe all
my ideas about brains and computers are false." The point remains that
*you* haven't *proven* that you're not a BIV. The skeptic hasn't proven
that you are a BIV either, of course; that's because all he's saying is that
we don't know one way or the other.
You could even question whether the BIV scenario is consistent with the laws
of nature. The skeptic will admit that we don't actually know what the laws
of nature are, so we cannot *prove* that the BIV scenario *is* consistent
with them. But nor can we prove that it *isn't*. And that's all he needs
for his premise - so the skeptic claims.
Maybe this will make it clearer: the skeptic's scenario doesn't have to draw
on actual brain science. The skeptic can put forward a hypothesis like
this: Maybe there are no human beings or other animals in the world. Maybe,
however, some species of trees are intelligent beings, who are able to move
around and stuff. Maybe the sensory experiences of trees are immediately
caused by vibrations in different parts of the surfaces of the leaves. And
maybe there is a tree-scientist who is keeping a big leaf in a dish
somewhere, poking it very precisely with a little vibrator, in just the
right way to cause it to have hallucinatory experiences of being a "human
being" (which is a fictional kind of entity from tree fairy tales). If this
were the case, your experiences would be just as they are now; so, how do
you know you're not a leaf in a dish?
According to the skeptic, this is just as good an argument as the BIV. Of
course there is no evidence of the existence of sentient trees, or anything
like that. But, there is no evidence against it either. Now, surely you're
not going to ask the skeptic, "How did you find out about the properties of
sentient trees?"
>Any attempt to prove (or disprove) the fundamental nature
>of perception, that is the relation between the world and us
>will lead to a circular argument (or a self-denying one)
>because the function of proof is to reason from the evidence
>of the senses.
Of course, the skeptic rejects this claim.
>Just look at all the knowledge the brain in vat scenario is
>dependent on. To pull it off would be one of the greatest
>intellectual achievments in all of human science.
>
>This doesn't exactly warrant an epistemological crisis, does it?
Sometimes, people make the following response: The skeptic claims that no
one has knowledge of the external world, because they could be BIV's. But
if you were a BIV, although *you* wouldn't have knowledge of the external
world, still the scientists would have to have knowledge of the external
world, right?
The skeptic will say: No. The scientists have to have true beliefs about
the world (e.g., they think they are stimulating a brain, and they are
stimulating a brain) in order for the BIV scenario to work. But the
scientists still do not have knowledge, since they themselves cannot give
any argument that *they* aren't BIV's. (Note the difference between
knowledge and true belief.) The BIV scenario implies, of course, that the
evil scientists are not themselves BIVs. But it doesn't imply that they
KNOW this.
In order to refute the skeptic, you would have to show: that in order to
argue "We don't know we're not BIV's", one must first assume a contingent
proposition about the external world. It seems that you think this is the
case, that in particular, one must use premises like "there are brains" and
"sensory experiences are caused by brain stimulation". But the skeptic will
say: No, it is enough for me to say we do not know that there aren't brains,
and we do not know that sensory experiences aren't caused by brain
stimulation, etc.
Why don't we know these things? Because you cannot offer any non-circular
argument for them.
One last thing. I mentioned before that the skeptic can pursue a *reductio
ad absurdum strategy*. He can say: "Look, I don't believe the senses are
valid means of knowledge. But let's suppose for the moment that they were.
*In that case*, since our sensory experiences attest to the existence of
brains, results of experiments on brains, and so on, *then* we would have to
conclude that brains exist, that sensory experiences are caused by brains,
and ultimately that a BIV scenario is in principle possible. Then we would
have to conclude that the senses are not legitimate means of knowledge after
all." Is the skeptic contradicting himself? No, that is how reductio ad
absurdum works: you show that the opponent's premise leads to its own
denial.
o
Owl
<19990712195806...@ng-fi1.aol.com>...
>Are you saying that if a human baby were transported into an alternate
reality
>where 1+1= 1/2, and 1-1 =4 (so you would reduce matter by adding to it, and
>expand matter by taking away from it) that the human mind by its nature
would
>always have a conflict with that, and never feel natural with it because
humans
>are bestowed with some magical "a priori" knowledge that 1+1=2?
No, I don't say that. What I would say is that the antecedent of that
conditional is incoherent. The hypothetical, "if a baby were transported to
an alternate reality where 1+1 = 1/2" makes no sense (does not describe any
coherently conceivable possibility). So there's no answer to the question
of what would happen after that. In other words: that 1 + 1 = 2 is a
necessary truth. All the traditional examples of a priori knowledge are
necessary truths, so in no case can you coherently ask what would happen to
a baby in a world in which one of the a priori propositions didn't hold.
(Aside: A logic professor of mine once asked, "If 7 were equal to 9, then
how much would be 3 times nine?" One student actually came up with a
number. The professor patiently informed her that the question didn't have
an answer.)
Again: There is no possible world in which there exists an aggregate
containing one unit of X and another (separate and distinct) unit of X, and
nothing else, such that this aggregate is not two units of X.
>I think that if your parents began drilling this 1+1=1/2 stuff into your
head
>since you were born, and also your teachers, and you saw it everyday around
>you, it would feel just as natural as 1+1=2.
If people kept telling me "1 + 1 = 1/2", then I would have learned that the
symbol "1/2" meant two. (Or perhaps I would have failed to understand what
"+" meant. Depends on the rest of what they said.)
>What you call
>"a priori" just seems to be fundamental properties of reality that of
course we
>cannot immagine any other way, because we live in this reality. But is that
any
>reason to say they are pre-packaged in our minds?
Careful: you're not going to ask me to entertain the inconceivable now, are
you?
o
Stephen Grossman
Chloride <n...@home.com> wrote:
> >Objectivists seem very confident that scepticism about the external
> >world can be conclusively refuted.
no, Objectivists claim that its not a cognitive claim at all but grunts
from a missing link. Uh, uh, ooh, eeeh, ahh, uh, eh?
Tom Runnacles <th...@elec.qmw.ac.uk
> >(1) If you were a brain in a vat on Mars,
if you were a brain in your own asshole, would you take a shit or let it
accumulate around your brain?
> The proof of this is that we are here and consious. That is, "I think
> therefore I am." The mere utterance of which is proof of the matter.
Im here and conscious. Youre not.
Keith Woodard
>In article <19990711142442...@ng-ch1.aol.com>,
> Jesus07312 <jesus...@aol.com> wrote:
>
>> >You're not totally certain you're criticizing Objectivists?
>>
>> Correct.
>
>Well, there's not really much point in addressing your criticisms when you're
>not even certain you're making them.
That's very good. Objectivists would do well to consider adopting
this as a general principle.
By ignoring the criticisms of anyone not claiming infallible knowledge
of objective reality, Objectivitists would realize a staggering
windfall of time to devote to their families, track their investment
portfolios, participate in extreme sports, and so on.
But here's a question for you, dbuel. Not a criticism, mind you.
Merely a question.
Do you have certain knowledge you're not a mind in a vat? If so, what
is your reasoning?
(Of course, think of the time savings inherent in the principle of
ignoring the *questions* of anyone not claiming infallible knowledge
of objective reality.)
Joseph J. Durnavich
>In order to refute the skeptic, you would have to show: that in order to
>argue "We don't know we're not BIV's", one must first assume a contingent
>proposition about the external world. It seems that you think this is the
>case, that in particular, one must use premises like "there are brains" and
>"sensory experiences are caused by brain stimulation". But the skeptic will
>say: No, it is enough for me to say we do not know that there aren't brains,
>and we do not know that sensory experiences aren't caused by brain
>stimulation, etc.
>
>Why don't we know these things? Because you cannot offer any non-circular
>argument for them.
The skeptic demands that we address his argument and prove we
are not BIVs. The difference between you and me is that you
accept the skeptic's challenge, whereas I immediately demand
he first demonstrate his argument is sound. Once you accept his
premise, essentially, "I imagine it, therefore, it might
be so" and debate on his terms, then you will never be able
to refute him.
Have you noticed that I never discussed whether *I* was or
could be a BIV or not? The arguments I have presented have
nothing to say one way or the other about whether I am
a BIV. That's because the skeptic's argument is fundamentally
flawed and can be rejected.
The skeptic's argument goes like the following. Here, "delusional"
means any of the hallucination or simulation scenarios we discussed:
P1: Joe Durnavich says he sees his coffee cup is empty.
P2: It is possible Joe is delusional.
P3: The burden of proof is on Joe to prove he is not delusional.
P4: Joe can offer no proof he is not delusional.
C: Therefore, Joe doesn't really know his coffee cup is empty.
P5: The same is true of any proposition Joe can state.
C: Therefore, Joe does not possess any true knowledge.
P6: The same is true of any proposition anyone can state.
C: Therefore, nobody possesses any true knowledge.
The way to deal with the skeptic is to make him establish
premise P2. The skeptic will make either of these mistakes:
(1) Assume that premise in concluding it. This is circular.
(2) Depend on perceptual knowledge. This contradicts his conclusion.
Consider premise P2: It is possible Joe is delusional. The
skeptic can
(A) Build us a brain in a vat to show us how a brain can be
deluded. That would be mistake (2).
(B) Present a hypothetical scenario suggesting a brain in
a vat or simular delusion and conclude from it that this
scenario is possible. This argument is interesting because
the skeptic argues from a hypothetical case to establish
a possibility in the real world. Typically, we use a
hypothetical case to extrapolate from things we do know to
discover other possibilities. The skeptic, however, wants
us to believe his hypothetical case is not based on any
knowledge whatsoever. "I imagine it. Therefore, it might
be so." Is this really baseless?
Look at the concepts he uses in the hypothetical cases: brain,
vat, computer, leaf, tree, sentient organism, vibration,
scientist, etc. These are all things the skeptic drew from
his perceptual experience. What kinds of things do people
hallucinate, dream of, or imagine: pink elephants, purple
chickens flying over and airless moon, a voice from a brick
fireplace stating complex mathematical equations, a large
clock folded over a chair, etc. Again, no matter how wild
these may be, they are still constructed from materials drawn
from perceptual experience.
The skeptic, then, is still making mistake number (2).
(C) The skeptic can point out that he might have been
delusional while learning the concepts he used in his hypothetical
scenario. The ideas in his head would be exactly the same as if
he learned them from a real reality. Therefore, his scenario does
not depend on real knowledge.
Of course, the skeptic makes mistake (1), circular argument,
because he is supposed to be establishing that it is possible to
be delusional.
(D) The skeptic can say: "Look, I don't believe the senses are
valid means of knowledge. But let's suppose for the moment that they were.
*In that case*, since our sensory experiences attest to the existence of
brains, results of experiments on brains, and so on, *then* we would have to
conclude that brains exist, that sensory experiences are caused by brains,
and ultimately that a BIV scenario is in principle possible. Then we would
have to conclude that the senses are not legitimate means of knowledge after
all." Is the skeptic contradicting himself? No, that is how reductio ad
absurdum works: you show that the opponent's premise leads to its own
denial.
The conclusion "the senses are not a legitimage means to
knowledge after all" does not follow from "BIVs are real
possibilities" unless one first accepts the skeptic's
argument. So that's mistake (1), circular argument.
---
Addressing your examples:
>Maybe this will make it clearer: the skeptic's scenario doesn't have to draw
>on actual brain science. The skeptic can put forward a hypothesis like
>this: Maybe there are no human beings or other animals in the world. Maybe,
>however, some species of trees are intelligent beings, who are able to move
>around and stuff. Maybe the sensory experiences of trees are immediately
>caused by vibrations in different parts of the surfaces of the leaves. And
>maybe there is a tree-scientist who is keeping a big leaf in a dish
>somewhere, poking it very precisely with a little vibrator, in just the
>right way to cause it to have hallucinatory experiences of being a "human
>being" (which is a fictional kind of entity from tree fairy tales). If this
>were the case, your experiences would be just as they are now; so, how do
>you know you're not a leaf in a dish?
>
>According to the skeptic, this is just as good an argument as the BIV. Of
>course there is no evidence of the existence of sentient trees, or anything
>like that. But, there is no evidence against it either. Now, surely you're
>not going to ask the skeptic, "How did you find out about the properties of
>sentient trees?"
How did he find out about "sentient," "trees," "leaf," "dish,"
"poking," "vibrator," etc.? This is all material of perceptual
experience. So, this argument is mistake (2). If you counter
that the skeptic may have been delusional while learning these
concepts, then you move to mistake (1), circular argument.
---
>Sometimes, people make the following response: The skeptic claims that no
>one has knowledge of the external world, because they could be BIV's.
That's premise P2 which he is supposed be establishing for us.
He's not ready to use it as a foregone conclusion.
>But
>if you were a BIV, although *you* wouldn't have knowledge of the external
>world, still the scientists would have to have knowledge of the external
>world, right?
>
>The skeptic will say: No. The scientists have to have true beliefs about
>the world (e.g., they think they are stimulating a brain, and they are
>stimulating a brain) in order for the BIV scenario to work. But the
>scientists still do not have knowledge, since they themselves cannot give
>any argument that *they* aren't BIV's. (Note the difference between
>knowledge and true belief.) The BIV scenario implies, of course, that the
>evil scientists are not themselves BIVs. But it doesn't imply that they
>KNOW this.
In other words, you assert premise P2 (and P3), it is possible
the scientists are delusional. But premise P2 is exactly what
the skeptic is supposed to establish for us. This whole argument
is mistake (1), circular argument, which an interesting twist:
It leads to an infinite regression of BIVs. BIVs all the
way down! Great science fiction idea. I love it!
---
Usually when we discuss epistemology, we examine the issues
solely by retreating inward and introspecting. It's easy
to fall into the trap, then, of thinking of your mental
contents as what you "really" know and that the goal
of philosophy is to try to match it up to the real world.
I suggest you go outside on a nice day, plant your feet
on the firm ground, feel its firmness, look up at the
blue sky, clouds, and trees, roads, cars, and houses
and say outloud to yourself with arms outstretched:
"This here is the mother of all axioms. This is The
Axiom. This is the referent of all my knowledge.
It makes no sense to ask if This might be an illusion
because it is in terms of This that I determine if
things are illusions or not. Every premise I assert,
every conclusion I draw, will all be related to This.
Just like every hill has its valley, every unreal I
posit will have This as its real."
--
Joe Durnavich
Greg Lange
>But here's a question for you, dbuel. Not a criticism, mind you.
>Merely a question.
>
>Do you have certain knowledge you're not a mind in a vat? If so,
>what is your reasoning?
I'll bite.
I know I'm not a brain in a vat because of the following:
1) I've never had any reason to suspect that I am. That is, I
know of no evidence suggesting this idea is true.
2) I have a great deal of evidence in support of the idea that
the world is real and I am a being with a material body living
in it.
3) I know, by introspection, that human beings can make up all
sorts of ideas which have no basis in reality. And, in light of
1), I suspect/am certain/know that the brain in vat scenarios
fall into that class of things.
Hence, by 1) - 3) above, I am certain (objectivist certain)
that I am not a brain in a vat.
Now, let me ask you a question or two.
Is there a valid purpose to your pursuit of ridiculous ideas?
If so, what?
Greg L. Lange
---
http://geocities.com/Athens/Delphi/4968/
---
End Transmission
_______________________________________________________________
Get Free Email and Do More On The Web. Visit http://www.msn.com
Keith Woodard
wrote:
>qwoo...@nospam.net (Keith Woodard) wrote:
>
>>But here's a question for you, dbuel. Not a criticism, mind you.
>>Merely a question.
>>
>>Do you have certain knowledge you're not a mind in a vat? If so,
>>what is your reasoning?
>
>I'll bite.
>
>I know I'm not a brain in a vat because of the following:
>
>1) I've never had any reason to suspect that I am. That is, I
>know of no evidence suggesting this idea is true.
Well, if the scientists wish you not to believe you're in the vat,
there'd be little point in their providing you with such evidence.
>2) I have a great deal of evidence in support of the idea that
>the world is real and I am a being with a material body living
>in it.
Yes, by hypothesis this is what they've been providing you with.
>3) I know, by introspection, that human beings can make up all
>sorts of ideas which have no basis in reality.
But nothing in this invalidates the possibility of imagining a
scenario which does happen to have a basis in reality.
> And, in light of
>1), I suspect/am certain/know that the brain in vat scenarios
>fall into that class of things.
Perhaps this is where we disagree. I consider "suspecting" and
"knowing for certain" to be two different things.
>Hence, by 1) - 3) above, I am certain
> (objectivist certain)
^^^^^^^^^^^^^^^
>that I am not a brain in a vat.
The parenthetical insertion makes me wonder if you might be using a
definition of certainty I'm unfamiliar with. Could this account for
our differences on this issue?
>Now, let me ask you a question or two.
>
>Is there a valid purpose to your pursuit of ridiculous ideas?
I think so.
>If so, what?
To me, the issue of what, if anything, we can be certain of has always
seemed important.
Keith Woodard
I think so.
>If so, what?
seemed important. So any thought that can shed light on that
question, no matter how ridiculous it might seem, is worthy of
consideration.
Jesus07312
>>What you call
>>"a priori" just seems to be fundamental properties of reality that of
>course we
>>cannot immagine any other way, because we live in this reality. But is that
>any
>>reason to say they are pre-packaged in our minds?
>
>
>Careful: you're not going to ask me to entertain the inconceivable now, are
>you?
I am not sure what you mean here. I am just wondering how you can justify this
concept of "a priori." If no one has ever been outside of our reality, in a
different one where 1+1 does not equal 2, so that we could do some testing to
see how their mind handled it, how do you deduce that our mind can know that
without any evidence of our reality?
-Jesus
Joe Durnavich
>>Ironically, sometimes when people say things like "I was certain I
>>left my keys on the kitchen table," they say it while looking at the
>>kitchen table and seeing the keys really aren't there like they
>>thought. "Certain" was an assessment of their state of knowledge.
>
>But they DID leave the keys on the table, they just aren't there now. They say
>they certainly left them on the table and mean "Reality is not any other way."
>They do not mean "I left my keys here, but further evidence might reveal t
>hat I
>actualy threw them out the window." If they have any doubts whether or not
> they
>left their keys there, they'd say "I think I left them there" or something
>similar. They are actualy certain that they left their keys on the table. They
>are not certain that no one else took them, and they would not claim that
>"I am
>certain that my keys will be on the table when i go look for them there"
>because they are not certain of this. The only thing they claim certainty of
>was putting the keys on the table, which they did. When they say this, they
>mean that further evidence will never be found to suggest that they actual
>y did
>something else with their keys, which is not the objectivist definition.
Only philosophers engage in such crazy-talk. Normal people don't
analyze everyday situations in such detail. The keys were dropped on
the table and were expected to be there a minute later.
A customer of ours was having a problem with one of our programs and
our salesman told me to send the 16-bit runtime because he was, and I
quote, "certain" it would fix the problem. That runtime did fix
similar problems in the past, but I thought we should investigate
further so we didn't waste time fixing a problem we didn't understand.
I came home for lunch and saw your post above and thought this would
be a good test of how normal people use the word "certain." During
lunch, he was so sure about the runtime, he convinced my boss to pull
me off a key project to send the runtime.
Well, the runtime didn't fix the problem. Someone was certain, but
later proved wrong. But so what? We learn from our mistake and plan
to do better in the future.
--
Joe Durnavich
Joe Durnavich
>(Aside: A logic professor of mine once asked, "If 7 were equal to 9, then
>how much would be 3 times nine?" One student actually came up with a
>number. The professor patiently informed her that the question didn't have
>an answer.)
There is that saying: 2 + 2 = 5 for sufficiently large values of 2.
--
Joe Durnavich
Owl
>The skeptic's argument goes like the following. Here, "delusional"
>means any of the hallucination or simulation scenarios we discussed:
>
>P1: Joe Durnavich says he sees his coffee cup is empty.
>P2: It is possible Joe is delusional.
>P3: The burden of proof is on Joe to prove he is not delusional.
>P4: Joe can offer no proof he is not delusional.
>C: Therefore, Joe doesn't really know his coffee cup is empty.
C follows from P3 and P4 alone. So the rest of your objections are
irrelevant.
>Look at the concepts he uses in the hypothetical cases: brain,
>vat, computer, leaf, tree, sentient organism, vibration,
>scientist, etc. These are all things the skeptic drew from
>his perceptual experience. What kinds of things do people
>hallucinate, dream of, or imagine: pink elephants, purple
>chickens flying over and airless moon, a voice from a brick
>fireplace stating complex mathematical equations, a large
>clock folded over a chair, etc. Again, no matter how wild
>these may be, they are still constructed from materials drawn
>from perceptual experience.
In the thread on a priori knowledge, I explained the difference between
understanding and justification. (A proposition can be understood but not
justified.) There is a distinction between saying, "Experiences cause me to
be able to understand P" and saying "Experiences justify P." It looks to me
as if your argument rests on the confusion between these things.
Experiences can cause you to form an idea without thereby justifying any
belief.
>(C) The skeptic can point out that he might have been
>delusional while learning the concepts he used in his hypothetical
>scenario. The ideas in his head would be exactly the same as if
>he learned them from a real reality. Therefore, his scenario does
>not depend on real knowledge.
>
>Of course, the skeptic makes mistake (1), circular argument,
>because he is supposed to be establishing that it is possible to
>be delusional.
No, you are missing the point. I said this to explain the difference
between justification and understanding, and to show you that not all
propositions are justified through experience.
The skeptic's statement above invalidates your earlier objection to his
argument by showing that the skeptic is NOT assuming that any of his
experiences were veridical. Since the skeptic is not assuming that, your
*first* objection fails. The skeptic's statement here is not intended to
prove that it's possible you could be a BIV; just to answer your objection
to it.
>(D) The skeptic can say: "Look, I don't believe the senses are
>valid means of knowledge. But let's suppose for the moment that they were.
>*In that case*, since our sensory experiences attest to the existence of
>brains, results of experiments on brains, and so on, *then* we would have
to
>conclude that brains exist, that sensory experiences are caused by brains,
>and ultimately that a BIV scenario is in principle possible. Then we would
>have to conclude that the senses are not legitimate means of knowledge
after
>all." Is the skeptic contradicting himself? No, that is how reductio ad
>absurdum works: you show that the opponent's premise leads to its own
>denial.
>
>The conclusion "the senses are not a legitimage means to
>knowledge after all" does not follow from "BIVs are real
>possibilities" unless one first accepts the skeptic's
>argument. So that's mistake (1), circular argument.
I don't know what you mean. It seems that you concede here that the skeptic
could get to "BIVs are real possibilities." Then you're somehow saying that
it doesn't follow that the senses are not a legitimate means of knowledge.
Why not? You say, "unless one first accepts the skeptic's argument". Which
argument? Which premise of it? Why?
Remember that with the reductio ad absurdum strategy, the skeptic gets to
assume all the premises that *you* think we know. Your earlier objections
were all to the effect that the skeptic had to rely on some common
sense-type knowledge, so they won't apply to the reductio strategy.
To sum up:
You claim that the skeptic needs to prove "BIV's are real possibilities",
and that he can't do so without relying on the senses. But
1. The skeptic's argument doesn't use that as a premise anyway.
2. In using ideas formed by the senses, one does not assume that sensory
perceptions were ever veridical.
3. Anyway, in the reductio ad absurdum strategy, it would be perfectly
legitimate to rely on the senses, in order to show that the senses aren't
valid.
o
Owl
<19990713203536...@ng-fu1.aol.com>...
>I am not sure what you mean here. I am just wondering how you can justify
this
>concept of "a priori." If no one has ever been outside of our reality, in a
>different one where 1+1 does not equal 2, so that we could do some testing
to
>see how their mind handled it, how do you deduce that our mind can know
that
>without any evidence of our reality?
I think you can anticipate that my answer to this question is the same as my
last answer. The phrase, "outside of our reality, in a different one where
1+1 does not equal 2" is incoherent. Compare the question, "If no one has
ever been in a situation where it is both raining and not raining at the
same time, how can we know how their mind would have handled it?" "It" at
the end doesn't refer to anything, since the antecedent doesn't state any
coherent scenario.
You're assuming we're talking about contingent propositions.
o
Iván Ordóñez
<greg_...@hotmail.com> wrote:
[...]
>I know I'm not a brain in a vat because of the following:
>
>1) I've never had any reason to suspect that I am. That is, I
>know of no evidence suggesting this idea is true.
Lack of belief and negative belief are different things. You are right in
not believing you are a BIV; you have no evidence that you are. But that
gives you no reason to positively believe you are *not* a BIV; you don't
have evidence to sustain that positive belief.
>2) I have a great deal of evidence in support of the idea that
>the world is real and I am a being with a material body living
>in it.
No, you don't. The BIV scenario is designed precisely to defeat that as
evidence.
>3) I know, by introspection, that human beings can make up all
>sorts of ideas which have no basis in reality. And, in light of
>1), I suspect/am certain/know that the brain in vat scenarios
>fall into that class of things.
Circumstantial. Not good as evidence.
>Hence, by 1) - 3) above, I am certain (objectivist certain)
>that I am not a brain in a vat.
A flawed reasoning, whatever kind of certainty you use.
--
Iván Ordóñez
http://www.cis.ohio-state.edu/~iordonez
email is iordonez at columbus dot rr dot com
Arnold Broese-van-Groenou
Joseph J. Durnavich <jo...@Mcs.Net> wrote in message
news:7mgfkm$1q33$1...@Jupiter.mcs.net...
>
> Have you noticed that I never discussed whether *I* was or
> could be a BIV or not? The arguments I have presented have
> nothing to say one way or the other about whether I am
> a BIV. That's because the skeptic's argument is fundamentally
> flawed and can be rejected.
I haven't included your argument with this reply, but it is well done.
--
A.Broese-van-Groenou.
aaa
Joe Durnavich
>Joseph J. Durnavich wrote in message <7mgfkm$1q33$1...@Jupiter.mcs.net>...
>>The skeptic's argument goes like the following. Here, "delusional"
>>means any of the hallucination or simulation scenarios we discussed:
>>
>>P1: Joe Durnavich says he sees his coffee cup is empty.
>>P2: It is possible Joe is delusional.
>>P3: The burden of proof is on Joe to prove he is not delusional.
>>P4: Joe can offer no proof he is not delusional.
>>C: Therefore, Joe doesn't really know his coffee cup is empty.
>
>
>C follows from P3 and P4 alone. So the rest of your objections are
>irrelevant.
Hey, they skeptic has to establish all of these premises, not just P2.
P2 was just the one you were bringing up over and over. The skeptic
will still either assume I have to prove I'm not delusional to have
knowledge, or draw from perceptual experiences to establish that. And
thus, we have reason to reject his argument.
And in case you still don't see this point: P3 is dependent on P2,
namely the idea that it is possible to be delusional (i.e., you might
be a BIV, whatever) and that this prevents you from having true
knowledge. The skeptic needs to establish all of these premises. If
you let him sit down at the table with them unquestioned, you'll never
get rid of him.
>>Look at the concepts he uses in the hypothetical cases: brain,
>>vat, computer, leaf, tree, sentient organism, vibration,
>>scientist, etc. These are all things the skeptic drew from
>>his perceptual experience. What kinds of things do people
>>hallucinate, dream of, or imagine: pink elephants, purple
>>chickens flying over and airless moon, a voice from a brick
>>fireplace stating complex mathematical equations, a large
>>clock folded over a chair, etc. Again, no matter how wild
>>these may be, they are still constructed from materials drawn
>>from perceptual experience.
>
>
>In the thread on a priori knowledge, I explained the difference between
>understanding and justification. (A proposition can be understood but not
>justified.) There is a distinction between saying, "Experiences cause me to
>be able to understand P" and saying "Experiences justify P." It looks to me
>as if your argument rests on the confusion between these things.
The skeptic has to justify those premises, that I can be deluded and
that delusion prevents me from having knowledge. This means he has to
justify that vibrations from trees can delude the senses. I just
listed the concepts above, rather, than your propositions that used
them to make you see a more general point that even though you gave up
on the BIV, your more fanciful scenario still draws on perceptual
knowledge. You don't exempt yourself from justification just because
you are spinning a science fiction scenario.
So, if you want to take another crack at it, what is it about trees
and vibrations that lead to you believe they can delude the senses?
And, ahem, how did you find this out? :-)
>Experiences can cause you to form an idea without thereby justifying any
>belief.
What kind of beliefs do you think our kid in the sensory depravation
tank is able to justify? Don't say he might be hooked up to and
learning from a simulator because that's what we are trying to
establish here.
>>(C) The skeptic can point out that he might have been
>>delusional while learning the concepts he used in his hypothetical
>>scenario. The ideas in his head would be exactly the same as if
>>he learned them from a real reality. Therefore, his scenario does
>>not depend on real knowledge.
>>
>>Of course, the skeptic makes mistake (1), circular argument,
>>because he is supposed to be establishing that it is possible to
>>be delusional.
>
>
>No, you are missing the point. I said this to explain the difference
>between justification and understanding, and to show you that not all
>propositions are justified through experience.
>
>The skeptic's statement above invalidates your earlier objection to his
>argument by showing that the skeptic is NOT assuming that any of his
>experiences were veridical.
In other words, the skeptic assumes he may be delusional (and that
this would prevent him from having true knowledge), i.e., premise P2,
exactly what I want him to establish before I accept his conclusion.
If the skeptic will avoid mistake (2) only at the expense of making
mistake (1).
>Since the skeptic is not assuming that, your
>*first* objection fails. The skeptic's statement here is not intended to
>prove that it's possible you could be a BIV; just to answer your objection
>to it.
Mike, notice that I'm objecting to the skeptic assuming that "he may
be delusional" (and that this might prevent him from having true
knowledge). This is what I want him to establish.
>>(D) The skeptic can say: "Look, I don't believe the senses are
>>valid means of knowledge. But let's suppose for the moment that they were.
>>*In that case*, since our sensory experiences attest to the existence of
>>brains, results of experiments on brains, and so on, *then* we would have
>to
>>conclude that brains exist, that sensory experiences are caused by brains,
>>and ultimately that a BIV scenario is in principle possible. Then we would
>>have to conclude that the senses are not legitimate means of knowledge
>after
>>all." Is the skeptic contradicting himself? No, that is how reductio ad
>>absurdum works: you show that the opponent's premise leads to its own
>>denial.
>>
>>The conclusion "the senses are not a legitimage means to
>>knowledge after all" does not follow from "BIVs are real
>>possibilities" unless one first accepts the skeptic's
>>argument. So that's mistake (1), circular argument.
>
>
>I don't know what you mean. It seems that you concede here that the skeptic
>could get to "BIVs are real possibilities." Then you're somehow saying that
>it doesn't follow that the senses are not a legitimate means of knowledge.
>Why not? You say, "unless one first accepts the skeptic's argument". Which
>argument? Which premise of it? Why?
The skeptic's argument in a nutshell is that because BIVs are
possible, the senses are not a legitimate means to knowledge--exactly
what you "conclude" above. I'm asking that he demonstrate the
soundness of this argument.
>Remember that with the reductio ad absurdum strategy, the skeptic gets to
>assume all the premises that *you* think we know. Your earlier objections
>were all to the effect that the skeptic had to rely on some common
>sense-type knowledge, so they won't apply to the reductio strategy.
Yes, but the skeptic can't assume his whole argument to make his
point!
>To sum up:
>You claim that the skeptic needs to prove "BIV's are real possibilities",
>and that he can't do so without relying on the senses. But
>1. The skeptic's argument doesn't use that as a premise anyway.
No, I'll build him a darn BIV if he wants. I want him to establish
the premises of his argument, especially that it is possible for me to
be delusional and that this would prevent me from having true
knowledge. (Feel free to restate the skeptic's premises. I was
trying to identify them and state them as general as I can.)
>2. In using ideas formed by the senses, one does not assume that sensory
>perceptions were ever veridical.
But this is premise P2, that he might be delusional. You accept this
as a foregone conclusion, but I think this is the area where we can
catch the skeptic. Now, I really don't care if he establishes it or
not. I just know he will make mistake (1) or mistake (2) while trying
to establish it.
>3. Anyway, in the reductio ad absurdum strategy, it would be perfectly
>legitimate to rely on the senses, in order to show that the senses aren't
>valid.
Yes, but you can't conclude the senses might not be valid, even if the
world was loaded with BIVs and vibrating leaves, unless you first
accept the skeptic's argument.
Mike I've looked over all your responses and there is not a single
case where you haven't made mistake (1) or mistake (2) in arguing as
the skeptic's advocate. I hope at some point you start to see that
the skeptic's argument itself is the problem.
--
Joe Durnavich
Jesus07312
>last answer. The phrase, "outside of our reality, in a different one where
>1+1 does not equal 2" is incoherent.
Okay, that was a bad scenario that I came up with.
But I still see how you can tell for sure whether or not you are just really
really really certain that 1+1=2 because you are surrounded by it everyday, and
because of all the evidence you have observed. To say that it does not depend
on evidence seems without justification to me.
Forget all of my scenarios. This is all I want to know: What -evidence- do you
have that suggests that we can know things like 1+1 = 2 without evidence?
-Jesus
Matt Ruff / Lisa Gold
>
> Matt Ruff wrote:
>
>> Gordon G. Sollars wrote:
>>
>>> Do you mean the certainty that comes from a logical deduction?
>>> Even there a mistake can be made. So what is "absolute certainty"?
>>
>> An unobtainable ideal, for the most part.
>
> Why bother with "for the most part"? When are your three conditions
> ever met?
I would tend to say they can be met in the case of simple logical and
mathematical proofs. Of course an extreme skeptic can doubt even this.
>>> As a good pragmatist, I don't think that is a very interesting
>>> notion of certainty.
>>
>> You don't think it's interesting, or you don't think it's useful? I
>> agree that absolute skepticism is useless as an approach to
>> day-to-day living, but I still enjoy reading Philip K. Dick novels.
>
> Interesting, sminteresting. I am a big fan of VALIS, too. I was
> thinking in terms of philosophy, not literature.
Yeah, well, thinking purely in terms of philosophy doesn't interest me
much.
>>> Why does "perfect illusion" imply "perfectly sustainable illusion"?
>>
>> I guess I assume that the only way to learn that an illusion is an
>> illusion is by finding a seam -- something about it that is
>> *different* from the thing it attempts to mimic, that allows it to
>> be distinguished from reality.
>
> That's fine; what I was getting at was that a "perfect illusion"
> does not imply (to me) an illusion that is /never/ detected.
Then I withdraw my question "Does it matter?" If the illusion is, or
will some day be, detectible -- if I can *do* something about it -- then
it probably does matter.
>> Yes, if I *learned* that my memories of having written SG&E were
>> false, that would be quite disturbing, and would make an immense
>> difference in my life.
>
> But how could you learn this?
I don't know, Gordon -- you're the one positing that the illusion is
detectible.
> What conditions would have to hold? I happen to have a copy of SG&E
> on the shelf behind me and I can see "Matt Ruff" on the spine. Now,
> perhaps it was written by another "Matt Ruff", or your name is not
> really "Matt Ruff", or the name is a pseudonym. But these cases do
> not show that there is no author of SG&E who has memories of writing
> it.
Ah, back to extreme skepticism. I don't know how you disprove extreme
skepticism, Gordon -- there are probably no proof conditions that could
withstand it. As for me, I just shrug, say "maybe so," and move on.
>>> You are certain that you wrote SG&E, at least as certain as you are
>>> of anything else.
>>
>> I believe that I wrote it, and would not seriously credit
>> unsubstantiated suggestions to the contrary (though I'm certainly
>> willing to consider the possibility as a thought experiment).
>
> What sort of "substantiation" could there be?
If there were a serious disruption in the continuity of my experience --
if I suddenly "woke up" in a different body, perhaps with a different
sensorium -- that, for example, would make me much more likely to credit
the idea that my previous experiences were false. Of course it would
also cause me to have serious doubts about *any* experiences I had
thereafter, and might well lead to madness. (Philip K. Dick covered this
topic fairly well in the short story "I Hope I Shall Arrive Soon.")
>> But if it happened that my belief was false, but I never *learned*
>> that it was false, nor knowingly suffered any consequences as a
>> result of it being false, I'm not sure what difference it would make
>> that it was false.
>
> Would it make no difference to you if your spouse had affairs
> (assuming you have agreed to remain faithful to each other), as
> long as you never learned about them?
What are you asking me:
(a) Do I care, in principle, whether my wife has affairs, even if she is
careful not to let me learn that she is having them? Answer: yes.
(b) If my wife actually does have an affair, but I never learn of it,
does it affect me? Answer: I don't think so, at least not directly.
Obviously the affair affects her, which in turn might affect our
relationship, but I don't see how knowledge that I don't possess can
affect me directly.
-- M. Ruff