The Zombie Poll

[Apathia]

since the experience of having one's brain replaced bit-by-bit would also certainly have a subjective impact as well.

I think that if the OP were here, he'd consider you on track.
other posters would seek to minimize this "subjective impact" thingy as much as possible, even to zilch, to spite the OP. lol

 

[Apathia]

'N den you drink it all up?

Precisely!

 

[Mercutio]

Ah - thank you. I wasn't aware of his departure; however, I would have continued my line of argument regardless, since the experience of having one's brain replaced bit-by-bit would also certainly have a subjective impact as well.

You have had your brain replaced bit-by-bit throughout your life, through the process of cell maintenance. The OP specifies that the replacement replicates exactly the function of the neuron it replaces. I think that the word "certainly" in your post is precisely the bone of contention in this thread. As I read it, we only can be certain of your "certainly" if we deny the "precisely the same function" of the OP. If we keep the "precisely the same function", then one's conclusions regarding "certainly" are dependent on your assumptions about the relationship of experience and brain.

Hyparxis-- "to spite the OP"? It sepecifies "precisely the same function". I think all are being true to the OP, which presents a question designed to examine the assumptions we bring to the table.

 

[Apathia]

Hyparxis-- "to spite the OP"? It sepecifies "precisely the same function". I think all are being true to the OP, which presents a question designed to examine the assumptions we bring to the table.

My opinion is UE had an argument in mind. Yes, step one, he was wanted to uncover a certain unpopular assumption that seems oh too Dualistic.
My opinion. Unfortunately we don't have him here to correct me.
Bottom line is, I do know he wanted a new thread similar to the Materialist one that new people could get into without reading that booklength backlog of posts or having him shout at them because they were bringing up old dead horse stuff that had already been kicked up the wazoo.

There has been some heavy contraying going on. Not by every poster.

 

[Paul C. Anagnostopoulos]

Bottom line is, I do know he wanted a new thread similar to the Materialist one that new people could get into without reading that booklength backlog of posts or having him shout at them because they were bringing up old dead horse stuff that had already been kicked up the wazoo.

Yup, and this ain't the last thread you'll see on the same subject.

I guess we could discuss what "precisely the same function" means. If certain brain architecture is required for QM to do its quantum gravity collapse thing (a la Penrose), then replacement parts with "precisely the same function" should work just as well. Unless, that is, QM is clever and knows when you're trying to fool it.

Contraying?

~~ Paul

 

[Mercutio]

I guess we could discuss what "precisely the same function" means.
~~ Paul

In Operant Conditioning, behaviors are defined by their function (as opposed to the topology of the behavior); it does not matter what the details of the movements are, what matters is what is accomplished. (as a simple example, it does not matter whether, in basketball, one shoots a foul shot right-handed, left-handed, two-handed, underhanded...what matters is whether or not it goes in.)

Given that the OP spoke of awareness and consciousness issues, the "function" is understood to be defined by those behaviors. If consciousness is dependent on nerve function, then that function is served--by definition in the OP--by the replacement. If, on the other hand, consciousness is not dependent on nerve function, then the replacement is irrelevant. Using the phrase "precisely the same function" renders the question trivial.

On the other hand....

One could argue that "function" may be defined mechanically, without regard to end result. (for the basketball example, one could build a machine--or train a person--to shoot a basketball with the perfect arc to sink a basket every time....and then aim it in a different direction, away from the basket. It performs exactly the right movements, but independently of context.) Given this definition, the problem is entirely different.

****

To me, the context of the OP clearly suggested the first scenario, and indeed "precisely the same function" is not the same as "precisely the same movements" or "precisely the same chemistry". Function is what something accomplishes, not what it does.

 

[Ichneumonwasp]

My opinion is UE had an argument in mind.

It's Searle's argument. I assumed he was headed in the same direction as Searle -- toward the concept of an "ontological subjectivity".

 

[chriswl]

My opinion is UE had an argument in mind. Yes, step one, he was wanted to uncover a certain unpopular assumption that seems oh too Dualistic.
My opinion. Unfortunately we don't have him here to correct me.
Bottom line is, I do know he wanted a new thread similar to the Materialist one that new people could get into without reading that booklength backlog of posts or having him shout at them because they were bringing up old dead horse stuff that had already been kicked up the wazoo.

Your reading far too much into the OP. Geoff stated that he wasn't going to get involved in this discussion, anyway, so there should be no problem continuing without him.

It's just the "fading qualia" argument. I believe this was first conceived by David Chalmers - he thought it was clearly ridiculous and introduced it as an example of a nonsensical thing that would have to be true if smooth transfer of consciousness was not possible. I am sure Chalmers is right on this.

Option B is John Searle's rather lame attempt to argue that fading qualia make sense (the text directly quotes Searle). It's a classic Searle argument - a complete unwillingness to take the issue seriously coupled with absolute conviction that everyone who disagrees with him is obviously stupid. He is truly my least favourite philosopher.

 

[Apathia]

It's Searle's argument. I assumed he was headed in the same direction as Searle -- toward the concept of an "ontological subjectivity".

Thanks. I didn't know where UE had gotten it only the drift of how he'd use it.

 

[jmercer]

You have had your brain replaced bit-by-bit throughout your life, through the process of cell maintenance. The OP specifies that the replacement replicates exactly the function of the neuron it replaces. I think that the word "certainly" in your post is precisely the bone of contention in this thread. As I read it, we only can be certain of your "certainly" if we deny the "precisely the same function" of the OP. If we keep the "precisely the same function", then one's conclusions regarding "certainly" are dependent on your assumptions about the relationship of experience and brain.

Hi, Merc - good to chat with you again.

Regarding neuron replacement in the brain... are you sure that's the case? I was under the impression that wasn't what was happening when neurons died - instead, I thought that the brain operates in a massively parallel fashion, so that when a neuron dies, another (or perhaps several others) are already handling the same functionality. In the case of massive trauma, even parallel systems take a loss... but if each neuron contains unique and irreplaceable information, wouldn't we be losing critical knowledge (and even maybe life functionality?) on an almost daily basis?

Doesn't sound like such a system would survive and flourish via the evolutionary process.

Anyway, regarding external replacement of cells... I guess my point is that replacing wetware with hardware may replicate functionality, but that's not the same thing as having the original.

I thought about this last night on my way home. (Man, do I need a life! ) After some thought, I came up with an analogy for us to bat around in case the topic continued in the thread.

This is a two-stage analogy - one is essentially a prep for the second, so please bear with me.

The Mona Lisa was painted by Da Vinci. If - by means of some kind of matter duplication process - we were able to replicate the original painting molecule by molecule, we'd have an absolutely perfect and physically indistinguishuable copy of the original.

Would an art collector knowingly pay as much for the duplicate as for the original?

I don't think so, but that's open for debate, of course.

The original was touched and created by Da Vinci himself; he mixed the pigments, applied the brushes, blended the various colors on the canvas by hand. The copy can't make that claim. Nor can the copy lay claim to the history of the painting and how it was handed down, or stolen, etc, etc. To that collector, there would be a real, non-subjective difference between the two items - the original would have a history associated with it, and the copy would merely be an extremely high-fidelity duplicate.

Sure, the collector might want the duplicate, since the original isn't really available for purchase, and is virtually priceless... but if given a choice between the original and copy, there's no doubt in my mind that a collector would always go for the original, and be willing to pay more for it than for the copy. We can debate whether the difference between the two is subjective or real... but regardless, there is a difference to collectors, historians... and probably the general public as well. I doubt seeing a duplicate would have the same impact as seeing the original for most people... part of the wonder is the thought that you're viewing something touched by Da Vinci himself.

Now let's forget about duplication and consider replacement - which is the second part of the analogy I referred to.

Suppose - over a period of time - we were able to replace the oil paint, canvas, etc., of the Mona Lisa with a virtually indistructable material. This material would indistinguishably mimic the color, texture, feel and weight of the original paint and canvas - but of course, would be chemically composed of an utterly different substance. Not a trace of a single molecule of the original painting would remain... but this would all happen "in-place", so there wouldn't be a duplicate involved, nor would there be a "discarded original". Instead, the replacement would happen "in-place".

Once completed... is the "new" Mona Lisa still the original? Or has the original been destroyed and replaced by a perfect duplicate?

I believe that the original has been destroyed; just as I believe that the original "me" would be destroyed by replacing my wetware with hardware.

 

[Ichneumonwasp]

Regarding neuron replacement in the brain

I don't think he meant "neuron replacement", but rather that all of the atoms in your body are constantly turning over, so that each of your neurons will consist of different building material than the original. This is true of all the cells in your body -- there is a constant turn-over-- and is simply a consequence of being alive. The underlying structure -- how the neurons are linked together and what they do-- is left in place, but the building material constantly turns over. If it did not, then errors would build in the proteins you use to live and we would die much earlier than we do.

Neurons are not easily replaced after cell death because once development is complete it is difficult for any neuron to know how to link up properly -- the signalling mechanism doesn't exist in the same way in a mature brain as it does in a developing brain.

Following your analogy, that means that the original "you" is constantly being replaced. If the original "you" consists in the atoms that make up your body, then "you" are no longer "you". There is a replicant in your place. Soon there will be a new replicant in the replicant's place. Sorry, it's biology.

 

[jmercer]

I don't think he meant "neuron replacement", but rather that all of the atoms in your body are constantly turning over, so that each of your neurons will consist of different building material than the original. This is true of all the cells in your body -- there is a constant turn-over-- and is simply a consequence of being alive. The underlying structure -- how the neurons are linked together and what they do-- is left in place, but the building material constantly turns over. If it did not, then errors would build in the proteins you use to live and we would die much earlier than we do.

Neurons are not easily replaced after cell death because once development is complete it is difficult for any neuron to know how to link up properly -- the signalling mechanism doesn't exist in the same way in a mature brain as it does in a developing brain.

Following your analogy, that means that the original "you" is constantly being replaced. If the original "you" consists in the atoms that make up your body, then "you" are no longer "you". There is a replicant in your place. Soon there will be a new replicant in the replicant's place. Sorry, it's biology.

Ok, but the natural process is one that supports full continuity, both in a physical and process sense. I also hesitate to classify the natural process as a "replacement" process; instead, I think it's better described as a "replenishment" process. Perhaps that's merely semantics, but maybe not.

Another difference is that the natural process is happening at an atomic level, not at a celluar level. The silicon example cited in this thread, however, would be a replacement at the celluar level. It would also introduce radically different molecular, chemical and biological processes. This is most emphatically not a replenishment, but is clearly a replacement process.

At the end of the artificial replacement, there would be no doubt that the individual had been altered - even the Mona Lisa examples I created would be more subtle and hard to detect. To me, this implies that such an obvious difference at the outset would be enough to say "This is not the original person, even if the persona is the same."

Just my take on it, of course...

 

[Ichneumonwasp]

The silicon example cited in this thread, however, would be a replacement at the celluar level. It would also introduce radically different molecular, chemical and biological processes. This is most emphatically not a replenishment, but is clearly a replacement process.

The silicon example isn't physically possible, so the whole thought experiment from that perspective is moot (as I had mentioned much earlier in the thread); but if it were possible to replace the biochemical doings of a cell and have it respond in precisely the same way as our neurons, then it would necessarily mimic the ways in which our neurotransmitters function, including the contributions from neuropeptides on G-protein complexes and the types of transmitters that can seep eyond the confines of cells -- like CO and NO.

There is simply no way that silicon chips can do any of that. For the thought experiment to work, you must view things a bit magically and in terms of function. We know that all the atoms of our bodies are replaced over time, so the actual building material changes over time leaving behind the structures that function in the same way as they always have (excepting the constant change in our nervous system with each new input). Replacing carbon with silicon that works in exactly the same fashion would simply amount to a slightly different building material that functions in exactly the same way (per the thought experiment). If the function is completely unchanged, then I don't see how there could be any difference between carbon and silicon. This could never work in the real world, but that never stopped any philosopher in his/her eternal quest for the most bizarre thought experiment.

If you look at it as silicon chips replacing our cells, there will very definitely be a change both in appearance and in function. But that violates the thought experiment in which function is supposed to remain unchanged. A silicon chip based brain could not, even in theory, be the same as a human wet-brain. A different person would result -- a different consciousness -- as was also discussed earlier in the thread.

The problem is that the thought experiment is a load of garbage.

 

[chriswl]

The problem with the OP is that some of the answers we are invited to consider actually contradict the assumptions in the question.

Gradual replacement of neurons by functionally identical duplicates ensures that brain activity is exactly the same as it would have been if the replacement had not been made. We can imagine two versions of the experiment. In one, the replacement of the neurons goes ahead as described. In the other the neurons are detatched but then simply put back in the same place, rather than being replaced by artificial ones. The patient is told that his brain is being replaced by an artificial one but no replacement actually happens. The assumption behind the thought experiment is that brain activity will be identical in both cases. The detaching and attaching of neurons, one at a time, will have no effect on brain function, either because all significant brain activity involves large groups of neurons or because the experimenters have come up with some incredibly fast and non-intrusive way of making the switch.

If we take these assumptions into account then the smooth transfer of consciousness seems to be the only possible result. If what happens is a fading away of consciousness then we would presumably be aware of this fading away and our awareness would imply different brain activity. But brain activity is causally determined by the neurons and we are strictly controlling these so that there can be no difference in the two cases (brain replacement versus non-replacement).

The argument practically compels us to believe that a functional duplicate of a human brain that duplicated the low-level structure (i.e. one amenable to piecemeal replacement) would have the same right to be considered conscious as a biological human brain.

 

[jmercer]

T
The problem is that the thought experiment is a load of garbage.

Agreed. Some months ago, there was a much better thread covering the same concept; the premise was matter transportation (a' la StarTrek). The process requires the destruction of the subject and creation (or re-creation) of a copy of the subject at the destination.

The question essentially was "Was the subject killed and a copy created? Or is it still the same person?"

It was a helluva thread.

 

[jmercer]

The argument practically compels us to believe that a functional duplicate of a human brain that duplicated the low-level structure (i.e. one amenable to piecemeal replacement) would have the same right to be considered conscious as a biological human brain.

Yep. It's a purely materialistic viewpoint, and the entire OP is effectively designed to support it's favored conclusion.

Or in other words, it's a straw man argument.

 

[Ichneumonwasp]

Just thinking, but a proper Mona Lisa analogy that mimics what happens with us biologically would run something along the lines of.....

The Louvre, in an attempt to maintain its biggest attendance draw, has been surreptitiously re-vamping the Mona Lisa over the past several centuries. Each year or so the painting is removed to a secret location so that paint that has faded can be replaced in precisely the same way that Leonardo did it. Over the past several centuries it so happens that all of the original paint that Leonardo used has been replaced with newer versions of paint. That represents the state of your body.

 

[Mercutio]

This is a two-stage analogy - one is essentially a prep for the second, so please bear with me.

The Mona Lisa was painted by Da Vinci. If - by means of some kind of matter duplication process - we were able to replicate the original painting molecule by molecule, we'd have an absolutely perfect and physically indistinguishuable copy of the original.

Would an art collector knowingly pay as much for the duplicate as for the original?

I don't think so, but that's open for debate, of course.

The original was touched and created by Da Vinci himself; he mixed the pigments, applied the brushes, blended the various colors on the canvas by hand. The copy can't make that claim. Nor can the copy lay claim to the history of the painting and how it was handed down, or stolen, etc, etc. To that collector, there would be a real, non-subjective difference between the two items - the original would have a history associated with it, and the copy would merely be an extremely high-fidelity duplicate.

Sure, the collector might want the duplicate, since the original isn't really available for purchase, and is virtually priceless... but if given a choice between the original and copy, there's no doubt in my mind that a collector would always go for the original, and be willing to pay more for it than for the copy. We can debate whether the difference between the two is subjective or real... but regardless, there is a difference to collectors, historians... and probably the general public as well. I doubt seeing a duplicate would have the same impact as seeing the original for most people... part of the wonder is the thought that you're viewing something touched by Da Vinci himself.

A good, but potentially misleading, example! The "misleading" bit is purely the fault of the Art world, though. Within this world, the provenance of the painting seems at times even more important than the painting itself! The Mona Lisa, for example, was stolen in 1911; suppose that the one hanging in the Louvre today is an exact copy? It is entirely possible that, if conlusive proof were produced today to show that it is currently a forgery, the museum would remove it from view, or at least alter the exhibit in some way. It would no longer be considered priceless. And what would have changed, compared to the same painting yesterday? Not a thing. Its value is not in its particular molecules, but in who put those molecules there. (The same can be said for paper money, compared to counterfeits.) There is no such requirement for our brains, except under some fairly strict (probably religious) assumptions.

Now let's forget about duplication and consider replacement - which is the second part of the analogy I referred to.

Suppose - over a period of time - we were able to replace the oil paint, canvas, etc., of the Mona Lisa with a virtually indistructable material. This material would indistinguishably mimic the color, texture, feel and weight of the original paint and canvas - but of course, would be chemically composed of an utterly different substance. Not a trace of a single molecule of the original painting would remain... but this would all happen "in-place", so there wouldn't be a duplicate involved, nor would there be a "discarded original". Instead, the replacement would happen "in-place".

Once completed... is the "new" Mona Lisa still the original? Or has the original been destroyed and replaced by a perfect duplicate?

I believe that the original has been destroyed; just as I believe that the original "me" would be destroyed by replacing my wetware with hardware.

I agree that the Mona Lisa would be considered to be destroyed by this process. For the reasons outlined above, though, I believe that this particular analogy does not work for the question in the OP.

(My thanks to Wasp for clarifying my previous post.)

 

[Ichneumonwasp]

The question essentially was "Was the subject killed and a copy created? Or is it still the same person?"

Yeah, it's an old philosophical chestnut. It's the problem of the ship of somewhere. I can't recall where the ship was supposed to be from -- replace all the planking slowly over time and is it the same ship?

 

[Mercutio]

Yeah, it's an old philosophical chestnut. It's the problem of the ship of somewhere. I can't recall where the ship was supposed to be from -- replace all the planking slowly over time and is it the same ship?

I saw a juggler in San Francisco once, with a great patter. He had a bit where he juggled a cleaver, a butcher's knife, and an axe. "This is the very axe that George Washington used to chop down the cherry tree. I had to have the handle replaced....and the head...but it occupies the same space as George Washington's axe..."