As a thought experiment, imagine we were to scan the position of every molecule in the human body to the Heisenberg limit of accuracy. Imagine we were to plug the resulting model in a physics simulation that models every biochemical and physical interaction with perfect fidelity. This is a thought experiment, and what I suggest isn't ruled out by physics, so let's assume it's technologically possible. Would the simulated being be "conscious" in the same way the original human is? Would it experience "qualia"?
If you think the answer might be no, then congratulations, you actually believe in immaterial souls, no matter how materialist or rationalist you otherwise claim to be.
Only holds if whatever hardware that’s pretending to be the matter can act exactly like the matter without being the same thing.
For the distinction, consider the difference between a simulation of a simple chemical process in a computer—even a perfectly accurate one!—and the actual thing happening. Is the thing going on in the computer the same? No, no matter how perfect the simulation. It’s a little electricity moving around, looking nothing whatsoever like the real thing. The simulation is meaning that we impose on that electricity moving around.
That being the case, this reduces to “if we recreate the matter and state exactly, for-real, is that consciousness?” in which case yeah, sure, probably so.
This doesn’t work if the thing running the simulation requires interpretation.
You can’t replace a body cell by cell, and you can’t know if it’d ever going to be possible. To just assume it certainly would is the same wild kind of extrapolation from past scientific progress as assuming we would be able to resist gravity or clip through walls would be in earlier times. There are natural laws that you don’t know about. That should be a hint about the issues with naive monistic materialism.
The same function, down to quantum and gravity et c effects on everything around it, and accepting and reacting to same? Yeah probably, but we’re back to having to “run” this on the same arrangement of actual matter as the original.
[edit] there’s an obvious attack on this, but I’ll go ahead and note my position on it: the whole premise that we can do any of this without just using actual matter the ordinary way is so far into magical territory that we might as well ask “what if lephuchans simulated it?” or “what if god imagined the simulation?”—well ok, sure, I guess if magic is involved that could work, but what’s the point of even considering it?
“What if a miracle occurred?” isn’t a rebuttal to the position that consciousness as we know it likely can’t be simulated by simulating physics, because you can rebut anything with it. Its admission to a discussion is the same as giving up on figuring out anything.
> there’s an obvious attack on this, but I’ll go ahead and note my position on it: the whole premise that we can do any of this without just using actual matter the ordinary way is so far into magical territory that we might as well ask “what if lephuchans simulated it?” or “what if god imagined the simulation?”—well ok, sure, I guess if magic is involved that could work, but what’s the point of even considering it?
That's one of the main points of using a thought experiment: by declaring axioms explicitly, by fiat ("true" by definition), it prevents the mind from taking advantage of thought terminating get out of jail free cards like this, it forces people to argue their point.
>It’s a little electricity moving around, looking nothing whatsoever like the real thing.
Why does "looking ... like the real thing" have any relevance for consciousness? What property of a conscious substance is captured by this "looking like" criteria? Is consciousness (partially) a feature of the substrate itself or how the substrate moves through some background consciousness aether, or something else? If you can't articulate what this special criteria is, then why think a simulation isn't conscious, which by assumption reproduces all information dynamics of the physical phenomena?
Are you questioning if physics is computable? Even if it is not fully, we must be able to approximate it quite well.
Suppose we scan more than just the person, but a local environment around them and simulated the whole box.
The update that occurs as the person sits in the room involves them considering their own existence. Maybe they create art about it. If the simulation is to produce accurate results, they will need to feel alive to themselves.
We agree we can simulate an explosion and get accurate results; if we can’t get an accurate simulation of a person, why?
exactly, The parent post does not address the issue of representation vs reality.
You can simulate every molecular interaction in a fire, but that does not mean the simulation gives off the same heat. You can write a perfectly accurate equation for splitting an atom, but the equation does not release energy.
> You can simulate every molecular interaction in a fire, but that does not mean the simulation gives off the same heat
It would to a simulated being standing next to the fire.
> You can write a perfectly accurate equation for splitting an atom, but the equation does not release energy.
It releases simulated energy inside the simulation.
Every material interaction is simulated. If you believe that consciousness can't exist in the simulation, then you believe that consciousness is not a material interaction, q.e.d.
It’s some electrons moving around. Any further meaning of that is only what we assign to it.
Unless your “computer” is identical matter in the same arrangement and state is the original, actually doing stuff.
This is why the “what if you slowly simulated the entire universe on an infinite beach moving rocks around to represent the state? Could anything in it be conscious?” thing isn’t my very interesting.
No, you’re just shoving rocks around on sand. They don’t mean anything except what you decide they do. Easy answer.
Doesn't materialism imply that a perfectly accurate simulation of the universe would be identical to the universe we live in? If not, in what possible way could the two be distinguished?
>Every material interaction is simulated. If you believe that consciousness can't exist in the simulation, then you believe that consciousness is not a material interaction
I think that is missing the point. You are literally changing the material and medium by conducting a simulation.
Releasing simulated energy within a simulation is not identical to releasing real energy in the real world. The former is purely representational, and even a perfectly simulated object retains this property, and lack of equivalence.
a simulated atom is not a real atom, no mater their similarlity.
When we refer to heat we refer to the increase in entropy that has specific effects to things in our world. We can also describe a generic "disordered" state, which doesn't imply a similar kind of causal compatibility. A simulation of entropy is equally disordered with no caveats despite not being exactly entropy due to the causal compatibility issue. Why think consciousness is like entropy rather than like disorder?
In other words, why think consciousness is a physical property of some specific kind of matter rather than an abstract property that can supervene on any sufficiently robust physical substrate?
>why think consciousness is a physical property of some specific kind of matter rather than an abstract property that can supervene on any sufficiently robust physical substrate?
Im open to the idea that consciousness could arise on different substrates, but hold that the substrate is relevant, and we dont have a working definition of "robustness".
This is part of a bigger challenge in which I claim there is no such thing as a perfect simulation.
Simulation requires representation, which requires requires remaining differences unrepresented. Otherwise you just have just created the same thing, not a simulation.
You can simulate the interaction of physical object with other physical objects using electronic object interacting with other electronic objects, but the two are not the same. The electronic object still can not interact with a physical object.
>Simulation requires representation, which requires requires remaining differences unrepresented
Right. But presumably not all physical properties of brains are necessary for consciousness. For example, the fact that action potentials happen on the order of 1ms to 1 second probably isn't intrinsic to consciousness. That is, there is no in principle problem with having consciousness supervene on neural networks that have much longer cycles for the basic substrate of communication. It also probably doesn't matter that neurons communicate through opening and closing ion channels, are made of carbon atoms, are constructed by protein assemblies produced from DNA, etc.
What we need is to represent every necessary feature and relationship involved in manifesting consciousness. As a first pass estimation, it seems very likely that only the information-bearing structures are necessary for consciousness. But the information-bearing structures are substrate independent. It follows that a perfect simulation of these information-bearing structures engaged in their typical dynamics would be conscious.
>You can simulate the interaction [...] but the two are not the same.
This idea that something needs to be "the same" is doing a lot of work in your argument. But most relationships involved in brains are incidental to consciousness. We need to get clear on what the necessary features of consciousness are. This is the only measure of sameness that matters, not superficial resemblance.
Scott Aaronson’s take on this is certainly worth a read for anyone interested in consciousness , quantum mechanics, comparability theory, etc: https://arxiv.org/abs/1306.0159
Instead of one person, simulate the earth starting several million years before the dawn of man. If you think the humans that evolve in some simulation runs are not conscious, you believe in souls. If in the fake world you predict that in some large fraction of simulations of the unfeeling simulacra will nonetheless invent and argue about the concept of qualia, you believe in immaterial souls. If you suspect that because they don’t have souls they won’t write books about qualia you believe in material souls, souls that both affect and are affected by protons and electrons, souls that physics will eventually find.
Not necessarily, this assumes that it is possible to perfectly simulate physics on computers. It is not obvious that this is true. For one it assumes that physical interactions happen in discrete time steps (or at least be equivalent with a process that happens in discrete time steps). It also assumes that it is possible to perfectly scan the all the properties of some piece of matter (which we know is not possible)
The “total scan” argument, when presented to further a physicalist stance (“surely if we were to scan you using some fantasy tech X we would get an exact copy of you, including any consciousness if it exists, and to deny that is to believe in ghosts”), is unconvincing on at least two counts: 1) fantasy tech illustrating axiomatic belief in particular physical models that are in vogue today but will not hold in the long run (Heisenberg limit? who is she?); and 2) believing that the only alternative to monistic materialism is body-soul dualism, which is depressingly common among STEM folk philosophical naïveté.
The most obvious objection is that perceived time-space is a map of some fundamentally inaccessible to us territory, that modern physical models on which the argument depends are likely only covering (imperfectly) a minuscule part of that territory, and that the map may never be fully precise and complete regardless of technology (since a map that is fully precise and complete is the territory).
As a sibling comment put, the Scott Aaronson post has lots of interesting questions about this. Do the aliens who are watching us being simulated inside matrix think we are actually conscious? What if they freeze the program for 100 years, or run the computation encrypted, or if the 'computer' is just a human inside a room shuffling papers?
Is the computer simulation of a water drop wet ?
I found this article [0] very insightful, where they basically propose that consciousness is relative to whom you ask. We inside the simulation may attribute consciousness to each other. The aliens running it may not. What is relevant is the degree of isomorphism between our simulated brain processes and their real ones. So things will advance from all these back-and-forth nebulous arguments only when neuroscience becomes able to explain mechanistically why people claim to be conscious.
> If you think the answer might be no, then congratulations, you actually believe in immaterial souls
If you scan a body of water, and simulate it perfectly, the resulting simulation will not be wet. You can't separate a material process from the material completely. Consciousness may be a result of carbon being a substrate in the interactions. It might be because the brain is wet when those processes happen. There is plenty of room between believing a perfect computational simulation is not conscious and believing in immaterial souls.
If you think the answer might be no, then congratulations, you actually believe in immaterial souls, no matter how materialist or rationalist you otherwise claim to be.