A few months ago, Rob Bensinger made a rather long post (that even got curated) in which he expressed his views on several questions related to personal identity and anticipated experiences in the context of potential uploading and emulation. A critical implicit assumption behind the exposition and reasoning he offered was the adoption of what I have described as the "standard LW-computationalist frame." In response to me highlighting this, Ruben Bloom said the following:

I differ from Rob in that I do think his piece should have flagged the assumption of ~computationalism, but think the assumption is reasonable enough to not have argued for in this piece.

I do think it is interesting philosophical discussion to hash it out, for the sake of rigor and really pushing for clarity. I'm sad that I don't think I could dive in deep on the topic right now.

However, as I pointed out in that thread, the lack of argumentation or discussion of this particular assumption throughout the history of the site means it's highly questionable to say that assuming it is "reasonable enough":

As TAG has written a number of times, the computationalist thesis seems not to have been convincingly (or even concretely) argued for in any LessWrong post or sequence (including Eliezer's Sequences).

TAG himself made a similar and important point in a different comment on the same post:

Naturalism and reductionism are not sufficient to rigourously prove either form of computationalism -- that performing a certain class of computations is sufficient to be conscious in general, or that performing a specific one is sufficient to be a particular conscious individual.

This has been going on for years: most rationalists believe in computationalism, none have a really good reason to.

Arguing down Cartesian dualism (the thing rationalists always do) doesn't increase the probability of computationalism, because there are further possibilities , including physicalism-without-computationalism (the one rationalists keep overlooking) , and scepticism about consciousness/identity.

One can of course adopt a belief in computationalism, or something else, in the basis of intuitions or probabilities. But then one is very much in the ream of Modest Epistemology, and needs to behave accordingly.

"My issue is not with your conclusion, it’s precisely with your absolute certainty, which imo you support with cyclical argumentation based on weak premises".

And, indeed (ironically enough), in response to andesoldes's excellent distillation of Rob's position and subsequent detailed and concrete explanation of why it seems wrong to have this degree of confidence in his beliefs, Bensinger yet again replied in a manner that seemed to indicate he thought he was arguing against a dualist who thought there was a little ghost inside the machine, an invisible homunculus that violated physicalism:

I agree that "I made a non-destructive software copy of myself and then experienced the future of my physical self rather than the future of my digital copy" is nonzero Bayesian evidence that physical brains have a Cartesian Soul that is responsible for the brain's phenomenal consciousness; the Cartesian Soul hypothesis does predict that data. But the prior probability of Cartesian Souls is low enough that I don't think it should matter.

You need some prior reason to believe in this Soul in the first place; the same as if you flipped a coin, it came up heads, and you said "aha, this is perfectly predicted by the existence of an invisible leprechaun who wanted that coin to come up heads!". Losing a coinflip isn't a surprising enough outcome to overcome the prior against invisible leprechauns.

But, as andesoldes later ably pointed out:

You're missing the bigger picture and pattern-matching in the wrong direction. I am not saying the above because I have a need to preserve my "soul" due to misguided intuitions. On the contrary, the reason for my disagreement is that I believe you are not staring into the abyss of physicalism hard enough. When I said I'm agnostic in my previous comment, I said it because physics and empiricism lead me to consider reality as more "unfamiliar"  than you do (assuming that my model of your beliefs is accurate). From my perspective, your post and your conclusions are written with an unwarranted degree of certainty, because imo your conception of physics and physicalism is too limited. Your post makes it seem like your conclusions are obvious because "physics" makes them the only option, but they are actually a product of implicit and unacknowledged philosophical assumptions, which (imo) you inherited from intuitions based on classical physics.

More specifically, as I wrote in response to Seth Herd, "[the] standard LW-computationalist frame reads to me as substantively anti-physicalist and mostly unreasonable to believe in" for reasons I gave in my explanation to Bloom:

What has been argued for, over and over again, is physicalism, and then more and more rejections of dualist conceptions of souls. 

That's perfectly fine, but "souls don't exist and thus consciousness and identity must function on top of a physical substrate" is very different from "the identity of a being is given by the abstract classical computation performed by a particular (and reified) subset of the brain's electronic circuit," and the latter has never been given compelling explanations or evidence. [1] This is despite the fact that the particular conclusions that have become part of the ethos of LW about stuff like brain emulation, cryonics etc are necessarily reliant on the latter, not the former. 

As a general matter, accepting physicalism as correct would naturally lead one to the conclusion that what runs on top of the physical substrate works on the basis of... what is physically there (which, to the best of our current understanding, can be represented through Quantum Mechanical probability amplitudes), not what conclusions you draw from a mathematical model that abstracts away quantum randomness in favor of a classical picture, the entire brain structure in favor of (a slightly augmented version of) its connectome, and the entire chemical make-up of it in favor of its electrical connections. As I have mentioned, that is a mere model that represents a very lossy compression of what is going on; it is not the same as the real thing, and conflating the two is an error that has been going on here for far too long. Of course, it very well might be the case that Rob and the computationalists are right about these issues, but the explanation up to now should make it clear why it is on them to provide evidence for their conclusion.

The accuracy of this interpretation of the LW-computationalist view seems to have been confirmed by its proponents, implicitly by Bensinger continuing the conversation with andesoldes without mentioning any disagreement when the latter explicitly asked him "First off, would you agree with my model of your beliefs? Would you consider it an accurate description?" and by cousin_it saying that "uploading [going] according to plan" means "the map of your neurons and connections has been copied into a computer", and explicitly by Seth Herd claiming that "your mind is a pattern instantiated in matter" and by Bloom, who wrote the following:

To answer your question in your other comment. I reckon with some time I could write an explainer for why we should very reasonable assume consciousness is the result of local brain stuff and nothing else (and also not quantum stuff), though I'd be surprised if I could easily write something so rigorous that you'd find it fully satisfactory.

(Emphasis mine.) 

When Seth Herd restated computationalist conclusions, once again without much argumentation ("Noncomputational physicalism sounds like it's just confused. Physics performs computations and can't be separated from doing that. Dual aspect theory is incoherent because you can't have our physics without doing computation that can create a being that claims and experiences consciousness like we do"), I summarized a relevant part of my skepticism as follows:

As I read these statements, they fail to contend with a rather basic map-territory distinction that lies at the core of "physics" and "computation." 

The basic concept of computation at issue here is a feature of the map you could use to approximate reality (i.e., the territory) . It is merely part of a mathematical model that, as I've described in response to Ruby earlier, represents a very lossy compression of the underlying physical substrate [2]. This is because, in this restricted and epistemically hobbled ontology, what is given inordinate attention is the abstract classical computation performed by a particular subset of the brain's electronic circuit. This is what makes it anti-physicalist, as I have explained:

[...]

So when you talk about a "pattern instantiated by physics as a pure result of how physics works", you're not pointing to anything meaningful in the territory, rather only something that makes sense in the particular ontology you have chosen to use to view it through, a frame that I have explained my skepticism of already.

So, to finish up the exposition and background behind this question, what are the actual arguments in favor of the computationalist thesis? If you agree with the latter philosophy,[1] why do you not think it to be the case that computationalism is anti-physicalist by failing a basic map-territory distinction due to how it reifies ideas like "computation" as being parts of the territory as opposed to mere artifacts of a mathematical model that attempts, imperfectly and lossily, to approximate reality?

  1. ^

    In my current model of this situation, I have some strong suspicions about the reasons why LW converged on this worldview despite the complete lack of solid argumentation in its favor, but I prefer to withhold the psychoanalysis and pathologizing of my interlocutors (at least until after the object-level matters are resolved satisfactorily).

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Steven Byrnes

147

A starting point is self-reports. If I truthfully say “I see my wristwatch”, then, somewhere in the chain of causation that eventually led to me uttering those words, there’s an actual watch, and photons are bouncing off it and entering my eyes then stimulating neurons etc.

So by the same token, if I say “your phenomenal consciousness is a salty yellow substance that smells like bananas and oozes out of your bellybutton”, and then you reply “no it isn’t!”, then let’s talk about how it is that you are so confident about that.

(I’m using “phenomenal consciousness” as an example, but ditto for “my sense of self / identity” or whatever else.)

So here, you uttered a reply (“No it isn’t!”). And we can assume that somewhere in the chain of causation is ‘phenomenal consciousness’ (whatever that is, if anything), and you were somehow introspecting upon it in order to get that information. You can’t know things in any other way—that’s the basic, hopefully-obvious point that I understand Eliezer was trying to make here.

Now, what’s a ‘chain of causation’, in the relevant sense? Let’s start with a passage from Age of Em:

The brain does not just happen to transform input signals into state changes and output signals; this transformation is the primary function of the brain, both to us and to the evolutionary processes that designed brains. The brain is designed to make this signal processing robust and efficient. Because of this, we expect the physical variables (technically, “degrees of freedom”) within the brain that encode signals and signal-relevant states, which transform these signals and states, and which transmit them elsewhere, to be overall rather physically isolated and disconnected from the other far more numerous unrelated physical degrees of freedom and processes in the brain. That is, changes in other aspects of the brain only rarely influence key brain parts that encode mental states and signals.

In other words, if your body temperature had been 0.1° colder, or if you were hanging upside down, or whatever, then the atoms in your brain would be configured differently in all kinds of ways … but you would still say “no it isn’t!” in response to my proposal that maybe your phenomenal consciousness is a salty yellow substance that oozes out of your bellybutton. And you would say it for the exact same reason.

This kind of thinking leads to the more general idea that the brain has inputs (e.g. photoreceptor cells), outputs (e.g. motoneurons … also, fun fact, the brain is a gland!), and algorithms connecting them. Those algorithms describe what Hanson’s “degrees of freedom” are doing from moment to moment, and why, and how. Whenever brains systematically do characteristically-brain-ish things—things like uttering grammatical sentences rather than moving mouth muscles randomly—then the explanation of that systematic pattern lies in the brain’s inputs, outputs, and/or algorithms. Yes, there’s randomness in what brains do, but whenever brains do characteristically-brainy-things reliably (e.g. disbelieve, and verbally deny, that your consciousness is a salty yellow substance that oozes out of your bellybutton), those things are evidently not the result of random fluctuations or whatever, but rather they follow from the properties of the algorithms and/or their inputs and outputs.

That doesn’t quite get us all the way to computationalist theories of consciousness or identity. Why not? Well, here are two ways I can think of to be non-computationalist within physicalism:

  • One could argue that consciousness & sense-of-identity etc. are just confused nonsense reifications of mental models with no referents at all, akin to “pure white” [because white is not pure, it’s a mix of wavelengths]. (Cf. “illusionism”.) I’m very sympathetic to this kind of view. And you could reasonably say “it’s not a computationalist theory of consciousness / identity, but rather a rejection of consciousness / identity altogether!” But I dunno, I think it’s still kinda computationalist in spirit, in the sense that one would presumably instead make the move of choosing to (re)define ‘consciousness’ and ‘sense-of-identity’ in such a way that those words point to things that actually exist at all (which is good), at the expense of being inconsistent with some of our intuitions about what those words are supposed to represent (which is bad). And when you make that move, those terms almost inevitably wind up pointing towards some aspect(s) of brain algorithms.
  • One could argue that we learn about consciousness & sense-of-identity via inputs to the brain algorithm rather than inherent properties of the algorithm itself—basically the idea that “I self-report about my phenomenal consciousness analogously to how I self-report about my wristwatch”, i.e. my brain perceives my consciousness & identity through some kind of sensory input channel, and maybe also my brain controls my consciousness & identity through some kind of motor or other output channel. If you believe something like that, then you could be physicalist but not a computationalist, I think. But I can’t think of any way to flesh out such a theory that’s remotely plausible.

I’m not a philosopher and am probably misusing technical terms in various ways. (If so, I’m open to corrections!)

(Note, I find these kinds of conversations to be very time-consuming and often not go anywhere, so I’ll read replies but am pretty unlikely to comment further. I hope this is helpful at all. I mostly didn’t read the previous conversation, so I’m sorry if I’m missing the point, answering the wrong question, etc.)

(Note, I find these kinds of conversations to be very time-consuming and often not go anywhere, so I’ll read replies but am pretty unlikely to comment further. I hope this is helpful at all. I mostly didn’t read the previous conversation, so I’m sorry if I’m missing the point, answering the wrong question, etc.)

That's fine. Your answer doesn't quite address the core of my arguments and confusions, but it's useful in its own right.

5Viliam
As I understood it, your objection was that computation is an abstraction/compression of the real thing, which is not the same as the real thing. (Is that correct?) First, let's check how important is the "compression" part. Imagine that someone would emulate your brain and body without compression -- in a huge computer the size of the Moon, faithfully, particle by particle, including whatever quantum effects are necessary (for the sake of thought experiment, let's assume that it is possible). Would such simulation be you in some sense? If we get that out of the way, I think that the part about compression was addressed. Lossy compression loses some information, but the argument was that consciousness is implemented in a robust way, and can survive some noise. Too much noise would ruin it. On the other hand, individual neurons die every day, so it seems like a quantitative question: it's not whether the simulation would be you, but how much would the simulation be you. Maybe simulating 50% of the neurons could still be 99% you, although this is just a speculation.

clone of saturn

110

I think the standard argument that quantum states are not relevant to cognitive processes is The importance of quantum decoherence in brain processes. This is enough to convince me that going through a classical teleporter or copying machine would preserve my identity, and in the case of a copying machine I would experience an equal subjective probability of coming out as the original or the copy. It also seems to strongly imply than mind uploading into some kind of classical artificial machine is possible, since it's unlikely that all or even most of the classical properties of the brain are essential. I agree that there's an open question about whether mind emulation on any arbitrary substrate (like, for instance, software running on CMOS computer chips) preserves identity even if it shows the same behavior as the original.

It also seems to strongly imply than mind uploading into some kind of classical artificial machine is possible, since it’s unlikely that all or even most of the classical properties of the brain are essential.

Could you say more about this? Why is this unlikely?

2clone of saturn
There seems to generally be a ton of arbitrary path-dependent stuff everywhere in biology that evolution hasn't yet optimized away, and I don't see a reason to expect the brain's implementation of consciousness to be an exception.
2the gears to ascension
Agreed about its implementation of awareness, as opposed to being unaware but still existing. What about its implementation of existing, as opposed to nonexistence?
2clone of saturn
Based on this comment I guess by "existing" you mean phenomenal consciousness and by "awareness" you mean behavior? I think the set of brainlike things that have the same phenomenal consciousness as me is a subset of the brainlike things that have the same behavior as me.
2the gears to ascension
Well I'd put it the other way round. I don't know what phenomenal consciousness is unless it just means the bare fact of existence. I currently think the thing people call phenomenal consciousness is just "having realityfluid".

in the case of a copying machine I would experience an equal subjective probability of coming out as the original or the copy

If you have a copying machine that is capable of outputting more than one (identical) copy, and you do the following:

  • first, copy yourself once
  • then, immediately afterwards, take that copy and copy it 9 times (for a total of 1 original and 10 copies)

Do you then expect a uniform 9.09% subjective probability of "coming out" of this process as any of the original + copies, or a 50% chance of coming out as the original and a 5% chance of coming out as any given copy?

2clone of saturn
If it's immediate enough that all the copies end up indistinguishable, with the same memories of the copying process, then uniform, otherwise not uniform.

Ape in the coat

20

I think we should disentangle "consciousness" from "identity" in general and when talking about computationalism in particular.

I don't think there is any reasonable alternative to computationalism when we are talking about the nature of consciousness. But this doesn't seem to actually imply that my "identity", whatever it is, will be necessary preserved during teleportation or uploading. I think at our current state of undertstanding, it's quite coherent to be computationalist about consciousness and eliminativist towards identity.

Signer

-1-5

Computationalism is an ethical theory, so it is fine for it to be based on high-level abstractions - ethics is arbitrary.

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the lack of argumentation or discussion of this particular assumption throughout the history of the site means it's highly questionable to say that assuming it is "reasonable enough"

While discussion on personal identity has mostly not received a single overarching post focusing solely on arguing all the details, it has been discussed to varying degrees of possible contention points. Thou Art Physics which focuses on getting the idea that you are made up of physics into your head, Identity Isn't in Specific Atoms which tries to dissolve the common intuition of the specific basic atoms mattering, Timeless Identity which is a culmination of various elements of those posts into the idea that even if you duplicate a person they both are still 'you'. There is also more, some of which you've linked, but I consider it strange to say that there's a lack of discussion. The sequence that the posts I've linked are a part of have other discussions, though I agree that they are often from the position of arguing against a baseline of dualism, but I believe they have many points that are relevant to an argument for computationalism. I think there is a lack of discussion about the very specific points you have a tendency to raise, but as I'll discuss, I find myself confused about their relevancy to varying degrees.

There's also the facet of decision theory posting that LW enjoys, which encourage this class of view. With decision problems like Newcomb's Paradox or Parfit's hitchhiker emphasizing the focus of "you can be instantiated inside a simulation to predict your actions, and you should act like that you — roughly — control their actions because of the similarity of your computational implementations". Of course, this works even without assuming the simulations are conscious, but I do think it has led to clearer consideration because it helps break past people's intuitions. Those intuitions are not made for the scenarios that we face, or will potentially have to face.

Bensinger yet again replied in a manner that seemed to indicate he thought he was arguing against a dualist who thought there was a little ghost inside the machine, an invisible homunculus that violated physicalism

Because most often the people suggesting such are dualists, or have a lot of the similar ideas even if they are discussed in an "I am uncertain" manner. I agree Rob could've given a better reply, but it was a reasonable assumption. (I personally found Andesolde's argument confused, with the later parts having a focus on first-person subjective experience that I think is not really useful to consider. There is uncertainties in there, but besides the idea that the mind could be importantly quantum in some way, didn't seem that relevant.)

That's perfectly fine, but "souls don't exist and thus consciousness and identity must function on top of a physical substrate" is very different from "the identity of a being is given by the abstract classical computation performed by a particular (and reified) subset of the brain's electronic circuit," and the latter has never been given compelling explanations or evidence.

I agree it hasn't been argued in depth — but there has definitely been arguments about the extent QM affects the brain. Of which, the usual conclusion was that the effect is minor, and/or that we had no evidence for believing it necessary. I would need a decently strong argument that QM is in some way computationally essential.

the entire brain structure in favor of (a slightly augmented version of) its connectome, and the entire chemical make-up of it in favor of its electrical connections.

More than just the electrical signals matter, this is understood by most. There's plenty of uncertainty about the level of detail needed to simulate/model the brain. Computationalism doesn't imply that only the electrical signals matter, it implies that whatever makes up the computation matters, which can be done via tiny molecules & electrons, water pipes, or circuitry. Simplifying a full molecular simulation to the functional implications of it is just one example of how far we can simplify, which I believe should extend pretty far.

"your mind is a pattern instantiated in matter"

I agree that people shouldn't assume that just neurons/connections are enough, but I doubt that is a strongly held belief; nor is it a required sub-belief of computationalism. You assume too much about Bensinger's reply when he didn't respond, especially as he was responding to subargument in the whole chain.
As well, the quoted sentence by Herd is very general — allowing both the neuron connections and molecular behavior. (There's also the fact that people often handwave over the specifics of what part of the brain you're extracting, because they're talking about the general idea through some specific example that people often think about. Such as a worm's neurons.)

For example, for two calculators, wouldn't you agree with a description of them as having the same 'pattern' even if all the atoms aren't in the same position relative to a table? You agree-reacted on one of dirk's comments:

https://www.lesswrong.com/posts/zPM5r3RjossttDrpw/when-is-a-mind-me?commentId=wziGLYTwM4Nb9gd6E I disagree that your mind is "a pattern instantiated in matter." Your mind is the matter. It's precisely the assumption that the mind is separable from the matter that I would characterize as non-physicalist.

Would the idea that a calculator has some pattern, some logical rules that it is implementing via matter, thus be non-physicalist about calculators? A brain follows the rules of reality, with many implications about how certain molecules constrain movement, how these neuron spikes cause hunger, etcetera. There is a logical/computational core to this that can be reimplemented.

The basic concept of computation at issue here is a feature of the map you could use to approximate reality (i.e., the territory) . It is merely part of a mathematical model that, as I've described in response to Ruby earlier, represents a very lossy compression of the underlying physical substrate

Why shouldn't we decide based on a model/category? Just as there's presumably edge-cases to what counts as a 'human' or 'person'. There very well may be strange setups which we can't reasonably determine to our liking whether we consider it computably implementing a person, a chihuahah, or the weather of Jupiter.
We could try to develop a theory of identity down to the last atom, still operating on a model but at least an extremely specific model, which would presumably force us to narrow in on confusing edge-cases. This would be interesting to do once we have the technology, though I expect there to be edge-cases no matter what, where our values aren't perfectly defined, which might mean preserving option value. I'm also skeptical that most methods present a very lossy compression even if we assume classical circuits. Why would it? (Or, if you're going to raise the idea of only getting some specific sub-class of neuron information, then sure, that probably isn't enough, but I don't care about that)

From this angle where you believe that computation is not fundamental or entirely well-defined, you can simplify the computationalist proposal as "merely" applying in a very large class of cases. Teleporters have no effect on personal identity due to similarity in atomic makeup up to some small allowance for noise (whether simple noise, or because we can't exactly copy all the quantum parts; I don't care if my lip atoms are slightly adjusted). Cloning does not have a strictly defined "you" and "not-you". Awakening from cryogenics counts as a continuation of you. A simulation implementing all the atomic interactions of your mind is very very likely to be you, and a simulation that has simplified many aspects of that down is also still very likely to be you.

Though there are definitely people who believe that the universe can fundamentally be considered computation, which I find plausible, especially due to a lack of other lenses that aren't just "reality is". Of which, your objection does not work without further argumentation with them.

Going back to the calculator example, you would need to provide argumentation for why the essential parts of the brain can't be implemented computationally.

(You link https://www.lesswrong.com/posts/zPM5r3RjossttDrpw/when-is-a-mind-me#5DqgcLuuTobiKqZAe ])

What I value about me is the pattern of beliefs, memories, and values.

The attempted mind-reading of others is (justifiably) seen as rude in conversations over the Internet, but I must nonetheless express very serious skepticism about this claim, as it's currently written. For one, I do not believe that "beliefs" and "values" ultimately make sense as distinct, coherent concepts that carve reality at the joints. This topic has been talked about before on LW a number of times, but I still fully endorse Charlie Steiner's distillation of it in his excellently-written Reducing Goodhart sequence

Concepts can still be useful categorizations even if they aren't hard and fast. Beliefs are often distinct from values in humans. They are vague and intertwine with each other, a belief forming a piece of value that doesn't fade away even once the belief is proven false, a value endorsing a belief for no reason... They are still not one and the same. I also don't see what this has relevance to in the statement. I agree with what they said. I value my pattern of beliefs, memories, and values. I don't care about my specific spatial position for identity (except insofar as I don't want to be in a star), or if I'm solely in baseline reality. They are vague and intertwine with each other, but they do behave differently. Your objections to CEV also seem to me to follow a similar pattern as this, where you go "this does not have a perfect foundational backing" to thus imply "it has no meaning, and there's nothing to be said about it". The consideration of path-dependency in CEV has been raised before, and it is an area that would be great to understand more. My values would say that I meta-value my beliefs to be closer to the truth. There are ambiguities in this area. What about beliefs affecting my values? There's more uncertainty in that region of what I wish to allow.

In any case, the rather abstract "beliefs, memories and values" you solely purport to value fit the category of professed ego-syntonic morals much more so than the category of what actually motivates and generates human behavior, as Steven Byrnes explained in an expectedly outstanding way:

I'd need a whole extra long comment to respond to all the various other parts of your comment chain. Such as indexicality, or the part which does the lines of saying "professed values are not real". Which seems decently false, overly cynical, and also not what Byrnes' linked post tries to imply. I'd say, professed values are often what you tend towards, but that your basic drives are often strong enough to stall out methods like "spend long hours solving some problem" due to many small opportunities. If you were given a big button to do something you profess to value, then you'd press it.

This also raises the question of: Why should I care that the human motivational system has certain basic drives driving it forward? Give me a big button and I'd alter my basic drives to be more in-line with my professed values. The basic drives are short-sighted. (Well, I'd prefer to wait until superintelligent help, because there's lots of ways to mess that up) Of course, that I don't have the big button has practical implications, but I'm primarily arguing against the cynical denial of having any other values than what these basic drives allow.


(I don't entirely like my comment, it could be better. I'd suggest breaking the parent question-post up into a dozen smaller questions if you want discussion, as the many facets could have long comments dedicated to each. Which is part of why there's no single post! You're touching on everything from theory of how the universe works, to how much the preferences we say are real, to whether our models of reality are useful enough for theories of identity, indexicality, whether it makes sense to talk about a logical pattern, etc. Then there's things like andesolde's posts that you cite, but I'm not sure I rely on, where I'd have various objections to their idea of reality as subjective-first. I'll probably find more I dislike about my comment, or realize that I could have worded or explained better once I come around to reading back over it with fresh eyes.)

While discussion on personal identity has mostly not received a single overarching post focusing solely on arguing all the details, it has been discussed to varying degrees of possible contention points. Thou Art Physics which focuses on getting the idea that you are made up of physics into your head, Identity Isn't in Specific Atoms which tries to dissolve the common intuition of the specific basic atoms mattering, Timeless Identity which is a culmination of various elements of those posts into the idea that even if you duplicate a person they both are still 'you'. There is also more, some of which you've linked, but I consider it strange to say that there's a lack of discussion.

I appreciate you linking these posts (which I have read and almost entirely agree with), but what they are doing (as you mentioned) is arguing against dualism, or in favor of physicalism, or against view classical (non-QM) entities like atoms have their own identity and are changed when copied (in a manner that can influence the fundamental identity of a being like a human).

What there has been a lack of discussion of is "having already accepted physicalism (and reductionism etc), why expect computationalism to be the correct theory?" None of those posts argue directly for computationalism; you can say they argue indirectly for it (and thus provide Bayesian evidence in its favor) by arguing against common opposing views, but I have already been convinced that those views are wrong.

And, as I have written before, physicalism-without-computationalism seems much more faithful to the core of physicalism (and to the reasons that convinced me of it in the first place) than computationalism does.

There's also the facet of decision theory posting that LW enjoys, which encourage this class of view. With decision problems like Newcomb's Paradox or Parfit's hitchhiker emphasizing the focus of "you can be instantiated inside a simulation to predict your actions, and you should act like that you — roughly — control their actions because of the similarity of your computational implementations". Of course, this works even without assuming the simulations are conscious, but I do think it has led to clearer consideration because it helps break past people's intuitions. Those intuitions are not made for the scenarios that we face, or will potentially have to face.

One man’s modus ponens is another man’s modus tollens. I agree that the LW-style decision theory posting encourages this type of thinking, and you seem to infer that the high-quality reasoning in the decision theory posts implies that they give good intuitions about the philosophy of identity.

I draw the opposite conclusion from this: the fact that the decision theory posts seem to work on the basis of a computationalist theory of identity makes me think worse of the decision-theory posts.

I agree it hasn't been argued in depth — but there has definitely been arguments about the extent QM affects the brain. Of which, the usual conclusion was that the effect is minor, and/or that we had no evidence for believing it necessary.

Can you link to some of these? I do not recall seeing anything like this here.

it implies that whatever makes up the computation matters

What is "the computation"? Can we try to taboo that word? My comment to Seth Herd is relevant here ("The basic concept of computation at issue here is a feature of the map you could use to approximate reality (i.e., the territory) . It is merely part of a mathematical model that, as I've described in response to Ruby earlier, represents a very lossy compression of the underlying physical substrate. [...] So when you talk about a "pattern instantiated by physics as a pure result of how physics works", you're not pointing to anything meaningful in the territory, rather only something that makes sense in the particular ontology you have chosen to use to view it through, a frame that I have explained my skepticism of already.) You seem to be thinking about computation as being some sort of ontologically irreducible feature of reality that can exist independently of a necessarily lossy and reductive mathematical model that tries to represent it, which doesn't make much sense to me.

I don't know if this will be helpful to you or not in terms of clarifying my thinking here, but I see this point here by you (asking "what makes up the computation") as being absolutely analogous to asking "what makes up causality," to which my response is, as Dagon said, that at the most basic level, I suspect "there's no such thing as causation, and maybe not even time and change.  Everything was determined in the initial configuration of quantum waveforms in the distant past of your lightcone.  The experience of time and change is just a side-effect of your embeddedness in this giant static many-dimensional universe."

Why shouldn't we decide based on a model/category?

Well, we can, but as I tried to explain above, I see this model as being very lossy and unjustifiably privileging the idea of computation, which does not seem to make sense to me as a feature of the territory as opposed to the map.

Your objections to CEV also seem to me to follow a similar pattern as this, where you go "this does not have a perfect foundational backing" to thus imply "it has no meaning, and there's nothing to be said about it".

I completely disagree with this, and I am confused as to what made you think I believe that "there's nothing to be said about [CEV]." I absolutely believe there is a lot to be said about CEV, namely that (for the reasons I gave in some of my previous comments that you are referencing and that I hope I can compile into one large post soon) CEV is theoretically unsound, conceptually incoherent, practically unviable, and should not be the target of any attempt to bring about a great future using AGI (regardless of whether it's on the first try or not).

That seems to me like the complete opposite of me thinking that there's nothing to be said about CEV.

Would the idea that a calculator has some pattern, some logical rules that it is implementing via matter, thus be non-physicalist about calculators? A brain follows the rules of reality, with many implications about how certain molecules constrain movement, how these neuron spikes cause hunger, etcetera. There is a logical/computational core to this that can be reimplemented.

I think it would be non-physicalist if (to slightly modify the analogy, for illustrative purposes) you say that a computer program I run on my laptop can be identified with the Python code it implements, because it is not actually what happens. 

We can see this as a result of stuff like single-event upsets, i.e., for example, situations in which stray cosmic rays modify the bits in a transistor in the physical entity that runs the code (i.e., the laptop) in such a manner that it fundamentally changes the output of the program. So the running of the program (instantiated and embedded in the real, physical world just like a human is) works not on the basis of the lossy model that only takes into account the "software" part, but rather on the "hardware" itself.

You can of course expand the idea of "computation" to say that, actually, it takes into account the stray cosmic rays as well, and in fact it takes into account everything that can affect the output, at which point "computation" stops being a subset of "what happens" and becomes the entirety of it. So if you want to say that the computation necessarily involves the entirety of what is physically there, then I believe I agree, at which point this is no longer the computationalist thesis argued for by Rob, Ruben etc (for example, the corolaries about WBE preserving identity when only an augmented part of the brain's connectome is scanned no longer hold).

One man’s modus ponens is another man’s modus tollens. I agree that the LW-style decision theory posting encourages this type of thinking, and you seem to infer that the high-quality reasoning in the decision theory posts implies that they give good intuitions about the philosophy of identity.

I draw the opposite conclusion from this: the fact that the decision theory posts seem to work on the basis of a computationalist theory of identity makes me think worse of the decision-theory posts.

Strongly seconding this.

I draw the opposite conclusion from this: the fact that the decision theory posts seem to work on the basis of a computationalist theory of identity makes me think worse of the decision-theory posts.

Why? If I try to guess, I'd point at not often considering indexicality as a consideration, merely thinking of it as having a single utility function which simplifies coordination. (But still, a lot of decision theory doesn't need to take into account indexicality..)
I see the decision theory posts as less as giving new intuitions, and more breaking old ones that are ill-adapted, though that's partially framing/semantics.

Can you link to some of these? I do not recall seeing anything like this here.

I'll try to find some, but they're more likely to be side parts of comment chains rather than posts, which does make them more challenging to search for. I doubt they're as in-depth as we'd like, I think there is work done there, even if I do think the assumption of QM not mattering much is likely.

The basic idea is what would it give you? If the brain uses it for a random component, why can't that be replaced with something pseudorandom? Which is fine from an angle of not seeing determinism as a problem. If the brain utilizes entangled atoms/neurons/whatever for efficiency, why can't those be replaced with another method — possibly impractically inefficient? Does the brain functionally depend on an arbitrary precision Real for a calculation, why would it, and what would be the matter if it was cut off to N digits?

There's certainly more, but finding specific comments I've read over the years is a challenge.

Everything was determined in the initial configuration of quantum waveforms in the distant past of your lightcone. The experience of time and change is just a side-effect of your embeddedness in this giant static many-dimensional universe."

I'm not sure I understand the distinction. Even if the true universe is a bunch of freeze-frame slices, time and change still functionally act the same. Given that I don't remember random nonsense in my past, there's some form of selection about which freeze-frames are constructed. Or, rather, with differing measure. Thus most of my 'future' measure is concentrated on freeze-frames that are consistent with what I've observed, as that has held true in the past.

Like, what you seem to be saying is Timeless Physics, of which I'd agree more with this statement:

An unchanging quantum mist hangs over the configuration space, not churning, not flowing. But the mist has internal structure, internal relations; and these contain time implicitly. The dynamics of physics—falling apples and rotating galaxies—is now embodied within the unchanging mist in the unchanging configuration space.

So I'd agree that computation only makes sense with some notion of time. That there has to be some way it is being stepped forward. (To me this is an argument in favor of not privileging spatial position in the common teleportation example, but we've seemed to move down a level to whether the brain can be implemented at all)

(bits about CEV) conceptually incoherent

I misworded what I say, sorry. I more meant that you consider it to say/imply nothing meaningful, but you can certainly still argue against it (such as arguing that it isn't coherent).

I think it would be non-physicalist if (to slightly modify the analogy, for illustrative purposes) you say that a computer program I run on my laptop can be identified with the Python code it implements, because it is not actually what happens.

I would say the that the computer program running can be considered as an implementation of the abstract python code. I agree that this model is missing details. Such as the exact behavior of the transistor, how fast it switches, the exact positions of the atoms, etcetera. That is dependent on the mind considering it, I agree. The cosmic ray event would make so it is no longer an implementation of the abstract python program. You could expand the consideration to include more of the universe. Just as you could expand your model to consider the computer program as an implementation of the python program with some constraints: that if this specific transistor gets flipped one too many times it will fry, that there's a slight possibility of a race condition that we didn't consider at all in our abstract implementation, there's a limit to the speed and heat it can operate at, a cosmic ray could come from these areas of space and hit it with 0.0x% probability thus disrupting functionality...

It still seems quite reasonable to say it is an implementation of the python program. I'm open to the argument that there isn't a completely natural privileged point of consideration from which the computer is implementing the same pattern as another computer, and that the pattern is this python program. But as I said before, even if this is ultimately some amount of purely subjective, it still seems to capture quite a lot of the possible ideas?

Like in mathematics, I can have an abstract implementation of a sorting algorithm and prove that a python program for a more complicated algorithm (bubblesort, whatever) is equivalent. This is missing a lot of details, but that same sort of move is what I'm gesturing at.

It is merely part of a mathematical model that, as I've described in response to Ruby earlier, represents a very lossy compression of the underlying physical substrate

I can understand why you think that just the neurons / connections is too lossy, but I'm very skeptical of the idea that we'd need all of the amplitudes related to the brain/mind. Apriori that seems unlikely whatwith how little fundamentally turns on the specifics of QM, and those that do can all be implemented specially. As I discussed above some.

(That also reminds me of another reason why people sometimes just mentions neurons/connections which I forgot in my first reply: because they assume you've gotten the basic brain architecture that is shared and just need to plug in the components that vary)

I disagree that this distinction between our model and reality has been lost, merely that it has been deemed not too significant, or as something you'd study in-depth when actually performing brain uploads.

What is "the computation"? Can we try to taboo that word?

As I said in my previous comment, and earlier in this one, I'm open to the idea of computation being subjective instead of a purely natural concept. Though I'd expect that there's not that many free variables in pinning down the meaning. As for tabooing, I think that is kind of hard, as one very simple way of viewing computation is "doing things according to rules".

You have an expression . This is in your mind and relies on subjective interpretations of what the symbols mean. You implement that abstract program (that abstract doing-things, a chain of rules of inference, a way that things interact) into a computer. The transistors were utilized because they matched the conceptual idea of how switches should function, but they have more complexities than the abstract switch, which introduces design constraints throughout the entire chip. The chip's ALU implements this through a bunch of transistors, which are more fundamentally made up of silicon in specific ways that regulate how electricity moves. There's layers and layers of complexities even as it processes the specific binary representations of the two numbers and shifts them in the right way. But, despite all this, all that fundamental behavior, all the quantum effects like tunneling which restrict size and positioning, it is computing the answer. You see the result, , and are pretty confident that no differences between your simple model of the computer and reality occurred.

This is where I think arguments about subjectivity of computation can be made. Introduce a person who is talking about a different abstract concept, they encode it as binary because that's what you do, and they have an operation that looks like multiplication and produces the same answer for that binary encoding. Then, the interpretation of that final binary output is dependent on the mind, because the mind has a different idea of what they're computing. (But with the abstract idea being different, even if those parts match up) But I think a lot of those cases are non-natural, which is part of why I think even if computation doesn't make sense as a fundamental thing or a completely natural concept, it still covers a wide area of concern and is a useful tool. Similar to how the distinction of values and beliefs is a useful tool even when strictly discussing humans, but even moreso. So then, the two calculators are implementing the same abstract algorithm in their silicon, and then we fall back to two questions 1) is the mind within the edge-cases such that it is not entirely meaningful to talk about an abstract program that it is implementing 2) okay, but even if they share the same computation, what does that imply. I think there could and should be more discussion of the complications around computation, with the easy to confuse interaction between levels of 'completely abstract idea' (platonism?), 'abstract idea represented in the mind' (what I'm talking about with abstract; subjective), 'the physical way that all the parts of this structure behave' (excessive detail but as accurate as possible; objective), 'the way these rules do a specific abstract idea' (chosen because of abstract ideas like a transistor is chosen because it functions like a switch, and the computer program is compiled in such a way because it matches the textual code you wrote which matches the abstract idea in your own mind; objective in that it is behaving in such a way, possibly subjective interpretation of the implications of that behavior).

We could also view computation through the lens of Turing Machines, but then that raises the argument of "what about all these quantum shenanigans, those are not computable by a turing machine". I'd say that finite approximations get you almost all of what you want. Then there's the objection of "turing machines aren't available as a fundamental thing", which is true, and "turing machines assume a privileged encoding", which is part of what I was trying to discuss above.

(I got kinda rambly in this last section, hopefully I haven't left any facets of the conversation with a branch I forgot to jump back to in order to complete)

We could also view computation through the lens of Turing Machines, but then that raises the argument of "what about all these quantum shenanigans, those are not computable by a turing machine".

I enjoyed reading your comment, but just wanted to point out that a quantum algorithm can be implemented by a classical computer, just with a possibly exponential slow down. The thing that breaks down is that any O(f(n)) algorithm on any classical computer is at worst O(f(n)^2) on a Turing machine; for quantum algorithms on quantum computers with f(n) runtime, the same decision problem can be decided in (I think) O(2^{(f(n)}) runtime on a Turing machine

These various ideas about identity don't seem to me to be things you can "prove" or "argue for". They're mostly just definitions that you adopt or don't adopt. Arguing about them is kind of pointless.

I suppose that actual ground-truth knowledge of what qualia are and how they arise might help, since a lot of people are going to wrap certain things about qualia into their ideas about identity... but that knowledge is not available.

Arguing about them is kind of pointless.

I absolutely disagree. The basic question of "if I die but my brain gets scanned beforehand and emulated, do I nonetheless continue living (in the sense of, say, anticipating the same kinds of experiences)?" seems the complete opposite of pointless, and the kind of conundrum in which agreeing or disagreeing with computationalism leads to completely different answers.

Perhaps there is a meaningful linguistic/semantic component to this, but in the example above, it seems understanding the nature of identity is decision-theoretically relevant for how one should think about whether WBE would be good or bad (in this particular respect, at least).

He didn't say the question is pointless, he said that arguing about them is kind of pointless.  It's an empirical question for which we have no good evidence.  The belief also pays no rent, unless you can actually get your brain scanned.

He didn't say the question is pointless, he said that arguing about them is kind of pointless.  It's an empirical question for which we have no good evidence.

... what? I'm confused what you're referring to.

He said the question was "mostly" a matter of "just definitions that you adopt or don't adopt." How is that an "empirical question"? And if we have "no good evidence" for it, why is a site moderator saying that the assumption of computationalism is so reasonable (and, implicitly, well-established) that you don't even need to argue for it in a curated post?

Moreover, I disagreed with his conclusion, and in any case, as has already been written about on this site many times, if you are actually just disputing definitions (as he claims we are), then you are dealing with a pointless (and even wrong) question. So, in this case, you can't say "arguing about them is kind of pointless" without also saying "the question is pointless."

do I nonetheless continue living (in the sense of, say, anticipating the same kinds of experiences)?

Does who continue living? The question isn't what experiences this or that copy or upload or person-who-came-out-of-the-transporter or whatever has. The question is generally who that copy/upload/etc is.

understanding the nature of identity

What I'm trying to say is that there is no actual "nature of identity".

Nobody's disagreeing about anything physical, or anything measurable, or even about the logical implications of some set of premises. People are saying "yes, that would still be me", or "no, that would not still be me", based on exactly the same facts (and often exactly the same anticipated experiences, depending on the "what has qualia" thing).

For a change of pace, I think it's useful to talk about behaviorism.

In this context, we're interpreting positions like "behaviorism" or "computationalism" as strategies for responding to the question "what are the differences that make a difference to my self?"

The behaviorist answers that the differences that make a difference are those that impact my behavior. But secretly, behaviorism is a broad class of strategies for answering, because what's "my behavior," anyhow? If you have a choice to put either a red dot or a blue dot on the back of my head, does that make a difference to my self even before I could possibly know what color the dot was, because if you make one choice me turning my head will be a "moving a blue dot behavior" while if you make the other choice it will be a "moving a red dot behavior"?

Your typical behaviorist will say that which color dot you put on my head has not caused a meaningful change. A description of my behavior isn't intended (by this hypothetical behaviorist) to be a complete description of all the atoms in the universe, or even all the atoms of my body. Instead, "my behavior" should be described in an ontology centered on what information I have access to through my senses, and what affordances I use to exhibit behavior. In such a blinkered and coarse-grained ontology, the "moving a blue dot behavior" and the "moving a red dot behavior" have identical descriptions as a "turning my head behavior."

This is useful to talk about, because the same song and dance still applies once you reject behaviorism.

Suppose some non-behaviorist answers that the It's not just my behavior that matters, but also what's going on inside. What's "what's going on inside", and why how's it different from "my behavior"?

Does "what's going on inside" require a description of all the atoms of my body? But that was one of the intermediate possibilities for "my behavior". And again, suppose I have some cells on the back of my head, and you can either dye them red, or dye them blue - it seems like that doesn't actually change what's going on inside.

So our typical non-behaviorist naturalist will say that a description of what's going on inside isn't intended to be a complete description of all the atoms in my body, instead "what's going on inside" should be described in an ontology centered on...

Well, here as someone with computationalist leanings I want to fill in something like "information flow and internal representations, in addition to my senses and behavioral affordances", and of course since there are many ways to do this, this is actually gesturing at a broad class of answers.

But here I'm curious if you'd want to fill in something else instead.