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Dude
SFN Die Hard

USA
6891 Posts

Posted - 05/18/2010 :  11:12:19  Show Profile Send Dude a Private Message  Reply with Quote
...to prove (valid premises, sound deductive argument style) that there is an external reality? I know we all accept it as a matter of pragmatism, and I personally think that the way in wich the world is ordered provides strong circumstantial evidence, but what would need to happen for us to be able to replace those very basic assumptions with actual direct evidence?

It's an old question, and it often comes up here in other topics, just thought it might be interesting to give it it's own thread.


Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson

"god :: the last refuge of a man with no answers and no argument." - G. Carlin

Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth

BigPapaSmurf
SFN Die Hard

3192 Posts

Posted - 05/18/2010 :  12:22:43   [Permalink]  Show Profile Send BigPapaSmurf a Private Message  Reply with Quote
Impossible, any arguement we make exists in the supposed external reality and is therefor suspect as it could have internal origins like everything else. Damnable sophisty!

"...things I have neither seen nor experienced nor heard tell of from anybody else; things, what is more, that do not in fact exist and could not ever exist at all. So my readers must not believe a word I say." -Lucian on his book True History

"...They accept such things on faith alone, without any evidence. So if a fraudulent and cunning person who knows how to take advantage of a situation comes among them, he can make himself rich in a short time." -Lucian critical of early Christians c.166 AD From his book, De Morte Peregrini
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BigPapaSmurf
SFN Die Hard

3192 Posts

Posted - 05/18/2010 :  12:31:02   [Permalink]  Show Profile Send BigPapaSmurf a Private Message  Reply with Quote
Though Ive never met anyone who actually believes this, It takes self-centered to a whole new literal and figurative extreme, to those who would argue it, "What am I, chopped liver?"

"...things I have neither seen nor experienced nor heard tell of from anybody else; things, what is more, that do not in fact exist and could not ever exist at all. So my readers must not believe a word I say." -Lucian on his book True History

"...They accept such things on faith alone, without any evidence. So if a fraudulent and cunning person who knows how to take advantage of a situation comes among them, he can make himself rich in a short time." -Lucian critical of early Christians c.166 AD From his book, De Morte Peregrini
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Machi4velli
SFN Regular

USA
854 Posts

Posted - 05/18/2010 :  14:05:13   [Permalink]  Show Profile Send Machi4velli a Private Message  Reply with Quote
What makes it external? If we knew about it, we'd probably just say it is part of reality. The idea that there could be more that we don't know about cannot really be argued against. The order we perceive is not good enough, as far as I'm concerned, to necessarily support anything.

If I'm not prepared to accept this same argument for intelligent design, it would be dishonest, I think, to accept it for anything else. In that case, people claim more based on this, but I don't think it's valid evidence for anything really. (With the exception of the idea that humans perceive in a similar way to each other.)

"Truth does not change because it is, or is not, believed by a majority of the people."
-Giordano Bruno

"The greatest enemy of knowledge is not ignorance, but the illusion of knowledge."
-Stephen Hawking

"Seeking what is true is not seeking what is desirable"
-Albert Camus
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Dude
SFN Die Hard

USA
6891 Posts

Posted - 05/18/2010 :  14:41:06   [Permalink]  Show Profile Send Dude a Private Message  Reply with Quote
Originally posted by Machi4velli

What makes it external? If we knew about it, we'd probably just say it is part of reality. The idea that there could be more that we don't know about cannot really be argued against. The order we perceive is not good enough, as far as I'm concerned, to necessarily support anything.

If I'm not prepared to accept this same argument for intelligent design, it would be dishonest, I think, to accept it for anything else. In that case, people claim more based on this, but I don't think it's valid evidence for anything really. (With the exception of the idea that humans perceive in a similar way to each other.)

The fundamental problem I'm asking about is the fact that we must assume there is a reality apart from ourselves. There is no logical argument or deductive proof to support any statement that claims there is anything outside of our own minds.

In order to function though, we all make two assumptions. There is an external reality and my senses can accurately detect it. Every statement about the universe we make rests on those two assumptions.

What I want to know is if there is any way (obviously hypothetical at this juncture) to actually investigate. What would constitute evidence for external reality actually being real or not?


Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson

"god :: the last refuge of a man with no answers and no argument." - G. Carlin

Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth
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Dave W.
Info Junkie

USA
26022 Posts

Posted - 05/18/2010 :  15:32:55   [Permalink]  Show Profile  Visit Dave W.'s Homepage Send Dave W. a Private Message  Reply with Quote
Originally posted by Dude

In order to function though, we all make two assumptions. There is an external reality and my senses can accurately detect it. Every statement about the universe we make rests on those two assumptions.
But they're not assumptions. Through observation and experiment, there seems to be an external reality, and it appears that my senses detect it as reliably as one should expect from mere biology. Through logic and metaphysics, however, I know this picture of reality might not be the truth. But, I also know that I will never be about to distinguish "true" reality from "false" reality, and so I am confined to what empiricism tells me as the best possible hypothesis.

Besides, the alternative is madness: any idea must be taken seriously. It's possible that the floors in my home are illusionary, and so if I were to try to stand in my bedroom, I would fall 20 feet to the ground below. So staying in bed is the only logical choice for self preservation. But it's also possible that the hunger I feel is a real signal that my body is starving, so getting up and leaving the room to find food is the only logical choice. Ignoring empiricism can only lead to a paralysis of opposing and evidence-free options.
What I want to know is if there is any way (obviously hypothetical at this juncture) to actually investigate. What would constitute evidence for external reality actually being real or not?
There cannot be any, since any external reality necessitates an interface between "mind" and "reality" (like eyes and ears, and the neurons which connect them to brains). And the only way to test the interface is by using the interface. There is no way to independently verify that the interface functions correctly, because we only have access to one side of it.

- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too.
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Dude
SFN Die Hard

USA
6891 Posts

Posted - 05/18/2010 :  17:12:45   [Permalink]  Show Profile Send Dude a Private Message  Reply with Quote
Dave_W said:
But they're not assumptions.

I disagree. I think there is strong reason to think they are true, but when it comes rght down to it you can't provide anything other than a circumstantial case for them.

There cannot be any, since any external reality necessitates an interface between "mind" and "reality" (like eyes and ears, and the neurons which connect them to brains). And the only way to test the interface is by using the interface. There is no way to independently verify that the interface functions correctly, because we only have access to one side of it.

That appears to contradict your position about them not being assumptions.


Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson

"god :: the last refuge of a man with no answers and no argument." - G. Carlin

Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth
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Dave W.
Info Junkie

USA
26022 Posts

Posted - 05/18/2010 :  17:36:48   [Permalink]  Show Profile  Visit Dave W.'s Homepage Send Dave W. a Private Message  Reply with Quote
Originally posted by Dude

I disagree. I think there is strong reason to think they are true, but when it comes rght down to it you can't provide anything other than a circumstantial case for them.
An assumption is something you just assume to be true. I'm not assuming that "there is an external reality," I'm constantly observing what appears to be an external reality and seeing that it behaves pretty much how I would expect it to.

This is little different from noting that nobody has ever found a Devonian Bunny with which to falsify evolution. If common descent is true, no such bunny will ever be found. The difference, of course, is that we have other, positive evidence for evolutionary theory, whereas my argument for an external reality is simply the repeated failure of observations to mismatch the model (and that in fact, that's all the empirical evidence we will ever have for it).
That appears to contradict your position about them not being assumptions.
I don't see why. You asked for deductive proof of an external reality (for which there is none) and then asked for anything that might count as empirical evidence (for which there can be none). My argument instead rests upon an induction.

- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too.
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Hawks
SFN Regular

Canada
1383 Posts

Posted - 05/18/2010 :  18:59:45   [Permalink]  Show Profile  Visit Hawks's Homepage Send Hawks a Private Message  Reply with Quote
In response to the claim that perceptions is all there is, Dr Samuel Johnson once kicked a stone and exclaimed "I refute it thus". Unfortunately, his simple refutation suffers from the same problem that all, by necessity, will: it is always possible that any experiments showing an external reality are, in fact, created by your own mind. Therefore, it is impossible to show that there exists an external reality.

METHINKS IT IS LIKE A WEASEL
It's a small, off-duty czechoslovakian traffic warden!
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Dude
SFN Die Hard

USA
6891 Posts

Posted - 05/18/2010 :  19:21:48   [Permalink]  Show Profile Send Dude a Private Message  Reply with Quote
Dave_W said:
An assumption is something you just assume to be true. I'm not assuming that "there is an external reality," I'm constantly observing what appears to be an external reality and seeing that it behaves pretty much how I would expect it to.

emphasis mine

If that isn't an assumption, then you are giving the word "assumption" a definition with wich I am not familiar.

I don't see why. You asked for deductive proof of an external reality (for which there is none) and then asked for anything that might count as empirical evidence (for which there can be none).

You don't see why that contradicts what you said in the previous paragraph?

My argument instead rests upon an induction.

Well, yes, and it also rests on those two very basic assumptions. They set the context for every other argument we make.

I don't disagree with your conclusion, but I am not convinced (as you apparently are) that there "can be no" empirical evidence. Hell if I can think of anything though.

Hawks said:
In response to the claim that perceptions is all there is, Dr Samuel Johnson once kicked a stone and exclaimed "I refute it thus". Unfortunately, his simple refutation suffers from the same problem that all, by necessity, will: it is always possible that any experiments showing an external reality are, in fact, created by your own mind. Therefore, it is impossible to show that there exists an external reality.

That is how I have always though on the issue as well, and still do.


Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson

"god :: the last refuge of a man with no answers and no argument." - G. Carlin

Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth
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Dave W.
Info Junkie

USA
26022 Posts

Posted - 05/18/2010 :  20:09:55   [Permalink]  Show Profile  Visit Dave W.'s Homepage Send Dave W. a Private Message  Reply with Quote
Originally posted by Dude

Dave_W said:
An assumption is something you just assume to be true. I'm not assuming that "there is an external reality," I'm constantly observing what appears to be an external reality and seeing that it behaves pretty much how I would expect it to.
emphasis mine

If that isn't an assumption, then you are giving the word "assumption" a definition with wich I am not familiar.
We make observations and create hypotheses about them. When disconfirmation fails, we reach a conclusion.

If your use of the word "assumption" were the way science were done, then everything about evolutionary theory that's failed to be falsified is an assumption. In other words, by assuming that common descent is true, we can make certain predictions about what we should find, and if our tests match those predictions, we no longer consider common descent assumed, we consider it confirmed. And the more our continued observations fail to disprove common descent, the more confirmed (and the less assumed) we consider it.

So I think you're conflating two meanings of the word "assumption," one from deductive logic, and the other from science.
I don't see why. You asked for deductive proof of an external reality (for which there is none) and then asked for anything that might count as empirical evidence (for which there can be none).

You don't see why that contradicts what you said in the previous paragraph?
Not at all. A failure to falsify a hypothesis is not the same thing as positive evidence in favor of it.
My argument instead rests upon an induction.
Well, yes, and it also rests on those two very basic assumptions. They set the context for every other argument we make.
No, the two assumptions you're referring to are valid, if weak, conclusions based on observations, the logical absurdity of their falsity, and the assumption that induction is valid. I'll grant the latter is an assumption, since without it, empiricism dies.
I don't disagree with your conclusion, but I am not convinced (as you apparently are) that there "can be no" empirical evidence. Hell if I can think of anything though.
All you need to do is find a way to empirically determine that your senses are reliable without using your senses to do it. That's why I think it's impossible.

Assume that you are a brain in a vat being fed a completely fictional reality via computer, and figure out a way to prove or falsify that you're a brain in a vat being fed a completely fictional reality.

My position is that for all practical intents and purposes, the fictional reality must be considered reality because there's no way to gather evidence in favor of the proposition that it isn't real. The "meta reality" of being a brain in a vat (which may have completely different laws of physics, chemistry, biology, etc.) is undetectable from inside the vat, and thus, like the God hypothesis, is completely worthless.

- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too.
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Ricky
SFN Die Hard

USA
4907 Posts

Posted - 05/18/2010 :  20:53:27   [Permalink]  Show Profile  Send Ricky an AOL message Send Ricky a Private Message  Reply with Quote
...and seeing that [reality] behaves pretty much how I would expect it to.


Your expectation is solely influenced by reality. I find the argument that what you've observed all your life behaves like what you've observed all your life to be rather unconvincing.

Why continue? Because we must. Because we have the call. Because it is nobler to fight for rationality without winning than to give up in the face of continued defeats. Because whatever true progress humanity makes is through the rationality of the occasional individual and because any one individual we may win for the cause may do more for humanity than a hundred thousand who hug their superstitions to their breast.
- Isaac Asimov
Edited by - Ricky on 05/18/2010 20:53:41
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Dude
SFN Die Hard

USA
6891 Posts

Posted - 05/19/2010 :  00:16:13   [Permalink]  Show Profile Send Dude a Private Message  Reply with Quote
Dave_W said:
We make observations and create hypotheses about them. When disconfirmation fails, we reach a conclusion.

Sure.

If your use of the word "assumption" were the way science were done, then everything about evolutionary theory that's failed to be falsified is an assumption.

No. Not within the context. It does rest on the assumption that what we are observing is real though. As we both agree, the other option is pointless, futile, and entirely unproductive. Doesn't change the fact that it all rests on those basic assumptions we make about reality.

In other words, by assuming that common descent is true, we can make certain predictions about what we should find, and if our tests match those predictions, we no longer consider common descent assumed, we consider it confirmed. And the more our continued observations fail to disprove common descent, the more confirmed (and the less assumed) we consider it.

Well, no. We started with a group of observations and followed those observations to a conclusion. Within that context we don't have to make any assumptions at all about evolution (except that we assume what we observe is real).

No, the two assumptions you're referring to are valid, if weak, conclusions based on observations, the logical absurdity of their falsity, and the assumption that induction is valid. I'll grant the latter is an assumption, since without it, empiricism dies.

So you do agree with me.

All you need to do is find a way to empirically determine that your senses are reliable without using your senses to do it. That's why I think it's impossible.

Well, yeah. It's probably impossible. I dislike the finality of proclaiming it is impossible though. I'm not convinced, entirely, that it's an impossible task. (unlike Ricky's SUV-pooping)


Ignorance is preferable to error; and he is less remote from the truth who believes nothing, than he who believes what is wrong.
-- Thomas Jefferson

"god :: the last refuge of a man with no answers and no argument." - G. Carlin

Hope, n.
The handmaiden of desperation; the opiate of despair; the illegible signpost on the road to perdition. ~~ da filth
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Dave W.
Info Junkie

USA
26022 Posts

Posted - 05/19/2010 :  10:39:22   [Permalink]  Show Profile  Visit Dave W.'s Homepage Send Dave W. a Private Message  Reply with Quote
Originally posted by Dude

No. Not within the context. It does rest on the assumption that what we are observing is real though. As we both agree, the other option is pointless, futile, and entirely unproductive. Doesn't change the fact that it all rests on those basic assumptions we make about reality.
No, the "other option" is solipsism, which is the null hypothesis. We have rejected it based on observation and logic, not merely by making assumptions that are more utilitarian.
Well, no. We started with a group of observations and followed those observations to a conclusion. Within that context we don't have to make any assumptions at all about evolution (except that we assume what we observe is real).
We have to assume that the scientific method works, and that induction is valid. Those assumptions are independent of whether or not there is an external reality. An internally consistent fever dream could include reams of "data" on "evolution" even though neither may be real.
No, the two assumptions you're referring to are valid, if weak, conclusions based on observations, the logical absurdity of their falsity, and the assumption that induction is valid. I'll grant the latter is an assumption, since without it, empiricism dies.
So you do agree with me.
I agree that at least one assumption is necessary. I disagree with you on what the necessary assumptions are.
Well, yeah. It's probably impossible. I dislike the finality of proclaiming it is impossible though. I'm not convinced, entirely, that it's an impossible task.
Well, I don't know how to explain it better. I don't like it, either, but the logic doesn't give a damn about which conclusions I might prefer.

- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too.
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Dave W.
Info Junkie

USA
26022 Posts

Posted - 05/19/2010 :  10:46:12   [Permalink]  Show Profile  Visit Dave W.'s Homepage Send Dave W. a Private Message  Reply with Quote
Originally posted by Ricky

Your expectation is solely influenced by reality. I find the argument that what you've observed all your life behaves like what you've observed all your life to be rather unconvincing.
Yes, my expectation is based upon my observations, just like our expectation of how electrons behave is based upon our observations of them. I can think of ways in which my observations might be different if "reality" were created entirely inside my own head, though, just like we can imagine ways in which electrons might behave if electron theory were false. And if we detect such falsifying conditions, we change or throw out the hypotheses.

The difference with reality is that I'm stuck inside the experiment, and cannot perturb the system from the outside. All I can do is wait for disconfirming evidence to arrive, which it may never do.

- Dave W. (Private Msg, EMail)
Evidently, I rock!
Why not question something for a change?
Visit Dave's Psoriasis Info, too.
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Machi4velli
SFN Regular

USA
854 Posts

Posted - 05/19/2010 :  20:36:26   [Permalink]  Show Profile Send Machi4velli a Private Message  Reply with Quote
Originally posted by Dave W.
If your use of the word "assumption" were the way science were done, then everything about evolutionary theory that's failed to be falsified is an assumption. In other words, by assuming that common descent is true, we can make certain predictions about what we should find, and if our tests match those predictions, we no longer consider common descent assumed, we consider it confirmed. And the more our continued observations fail to disprove common descent, the more confirmed (and the less assumed) we consider it.

It is confirmed with respect to an assumed basis, assumed idea of causation, assumed validity of empiricism though, right?

"Truth does not change because it is, or is not, believed by a majority of the people."
-Giordano Bruno

"The greatest enemy of knowledge is not ignorance, but the illusion of knowledge."
-Stephen Hawking

"Seeking what is true is not seeking what is desirable"
-Albert Camus
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