I think the physical functionalist could go either way on whether a physically embodied robot wouldn’t be conscious.
Just clarifying this. A physical functionalist could coherently maintain that it’s not possible to build an embodied AI robot because physics doesn’t allow it. Similar to how a wooden rod can burn but a steel rod can’t because of the physics. But assuming that it’s physically possible to build an embodied AI system which passes behavioural tests of consciousness e.g. self-recognition, cross-modal binding, flexible problem solving etc.. then the physical functionalist would maintain that the system is conscious.
I think looking at how neurons actually work would probably resolve the disagreement between my inner A and S. Like, I do think that if we knew that the brain’s functions don’t depend on sub-neuron movements, then the neuron-replacement argument would just work
Out of interest, do you or @sunwillrise have any arguments or intuitions that the presence or absence of consciousness turns on sub-neuronal dynamics?
Consciousness appears across radically different neural architectures; octopuses with distributed neural processing in their arms, birds with a nucleated brain structure called the pallium which differs from the human cortex but has similar functional structure, even bumblebees are thought to possess some form of consciousness with far fewer neuron counts than humans. These examples exhibit coarse-grained functional similarities with the human brain—but differ substantially at the level of individual neurons.
If sub-neuronal dynamics determined presence or absence of consciousness we’d expect minor perturbations to erase it. Instead we’re able to lesion large brain regions whilst maintaining consciousness. You also preserve consciousness when small sub-neuronal changes are applied to every neuron such as when someone takes drugs like alcohol or caffeine. Fever also alters reaction rates and dynamics in every neuron across the brain. This robustness indicates that presence or absence of consciousness turns on coarse-grained functional dynamics rather than sub-neuronal dynamics.
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). 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.
More specifically, is a real-world being actually the same as the abstract computation its mind embodies? Rejections of souls and dualism, alongside arguments for physicalism, do not prove the computationalist thesis to be correct, as physicalism-without-computationalism is not only possible but also (as the very name implies) a priori far more faithful to the standard physicalist worldview.
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The feedback loops implicit in the structure of the brain cause reward and punishment signals to “release chemicals that induce the brain to rearrange itself” in a manner closely analogous to and clearly reminiscent of a continuous and (until death) never-ending micro-scale brain surgery. To be sure, barring serious brain trauma, these are typically small-scale changes, but they nevertheless fundamentally modify the connections in the brain and thus the computation it would produce in something like an emulated state (as a straightforward corollary, how would an em that does not “update” its brain chemistry the same way that a biological being does be “human” in any decision-relevant way?). We can think about a continuous personal identity through the lens of mutual information about memories, personalities etc, but our current understanding of these topics is vastly incomplete and inadequate, and in any case the naive (yet very widespread, even on LW) interpretation of “the utility function is not up for grabs” as meaning that terminal values cannot be changed (or even make sense as a coherent concept) seems totally wrong.
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”.
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. By this I mean the following:
It seems to me that when you think about physics, you are modeling reality (I intentionally avoid the word “universe” because it evokes specific mental imagery) as a “scene” with “things” in it. You mentally take the vantage point of a disembodied “observer/narrator/third person” observing the “things” (atoms, radiation etc) moving, interacting according to specific rules and coming together to create forms. However, you have to keep in mind that this conception of reality as a classical “scene” that is “out there” is first and foremost a model, one that is formed from your experiences obtained by interacting specifically with classical objects (biliard balls, chairs, water waves etc). You can extrapolate from this model and say that reality truly is like that, but the map is not the territory, so you at least have to keep track of this philosophical assumption. And it is an assumption, because “physics” doesn’t force you to conclude such a thing. Seen through a cautious, empirical lens, physics is a set of rules that allows you to predict experiences. This set of rules is produced exclusively by distilling and extrapolating from first-person experiences. It could be (and it probably is) the case that reality is ontologically far weirder than we can conceive, but that it still leads to the observed first-person experiences. In this case, physics works fine to predict said experiences, and it also works as an approximation of reality, but this doesn’t automatically mean that our (merely human) conceptual models are reality. So, if we want to be epistemically careful, we shouldn’t think “An apple is falling” but instead “I am having the experience of seeing an apple fall”, and we can add extra philosophical assumptions afterwards. This may seem like I am philosophizing too much and being too strict, but it is extremely important to properly acknowledge subjective experience as the basis for our mental models, including that of the observer-independent world of classical physics. This is why the hard problem of consciousness is called “hard”. And if you think that it should “obviously” be the other way around, meaning that this “scene” mental model is more fundamental than your subjective experiences, maybe you should reflect on why you developed this intuition in the first place. (It may be through extrapolating too much from your (first-person, subjective) experiences with objects that seemingly possess intrinsic, observer-independent properties, like the classical objects of everyday life.)
At this point it should be clearer why I am disagreeing with your post. Consciousness may be classical, it may be quantum, it may be something else. I have no issue with not having a soul and I don’t object to the idea of a bunch of gears and levers instantiating my consciousness merely because I find it a priori “preposterous” or “absurd” (though it is not a strong point of your theory). 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 I find it confusing that your post is receiving so much positive attention on a forum where epistemic hygiene is supposedly of paramount importance.
Just clarifying this. A physical functionalist could coherently maintain that it’s not possible to build an embodied AI robot because physics doesn’t allow it. Similar to how a wooden rod can burn but a steel rod can’t because of the physics. But assuming that it’s physically possible to build an embodied AI system which passes behavioural tests of consciousness e.g. self-recognition, cross-modal binding, flexible problem solving etc.. then the physical functionalist would maintain that the system is conscious.
Out of interest, do you or @sunwillrise have any arguments or intuitions that the presence or absence of consciousness turns on sub-neuronal dynamics?
Consciousness appears across radically different neural architectures; octopuses with distributed neural processing in their arms, birds with a nucleated brain structure called the pallium which differs from the human cortex but has similar functional structure, even bumblebees are thought to possess some form of consciousness with far fewer neuron counts than humans. These examples exhibit coarse-grained functional similarities with the human brain—but differ substantially at the level of individual neurons.
If sub-neuronal dynamics determined presence or absence of consciousness we’d expect minor perturbations to erase it. Instead we’re able to lesion large brain regions whilst maintaining consciousness. You also preserve consciousness when small sub-neuronal changes are applied to every neuron such as when someone takes drugs like alcohol or caffeine. Fever also alters reaction rates and dynamics in every neuron across the brain. This robustness indicates that presence or absence of consciousness turns on coarse-grained functional dynamics rather than sub-neuronal dynamics.
I will point to what I (and others) have commented on or posted about before, and I shall hope that’s an adequate answer to your question.
I have written:
I have also written:
TAG has written:
Andesoldes has written: