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