> there is absolutely, undeniably, a correlation between brain states and mental states -- but that does not entail that mental states reduce to or are explained entirely by brain states
It's not plain correlation. It's long been experimentally demonstrated that you can circuit-bend[0] an animal or a human live, by poking in their brain[1]. If in those cases, altering brain state creates/affects behavior and mental states, then there isn't really a place for a non-physical-stuff consciousness. If it existed, it's demonstrably overridable by purely physical interventions, which implies you could just make a physical-stuff consciousness, at which point why postulate a non-material one?
Poking at the brain or consuming certain substances causes changes in the phenomena experienced in consciousness.
But doesn’t seem in any way explanatory of consciousness itself, i.e. the owner of the brain’s awareness of those state changes.
I think this points at the somewhat nebulous definition of consciousness, which at its core seems categorically separate from the phenomena that can be experienced (and manipulated by poking at the brain) within it.
This is why some have theorized that everything is conscious, and the human experience of consciousness just happens to be particularly rich and complex due to the complexity of the human organism. This would suggest that a sufficiently advanced computer could also be conscious, with the specific experience mediated by the architecture of the computer.
(I’m not endorsing this position, but it’s an interesting thought experiment to help separate experiences in consciousness from consciousness itself).
I never denied the claim that changing the brain can change mental states. I think that the experiences we have are ones we have because of physical states (primarily, the brain). I just do not think that the experiences themselves are physical things, and on a purely naturalistic explanation of the universe experiences would not exist.
You are right that on naturalism there isn't really a place for non-physical-stuff consciousness. And yet, the existence of non-physical-stuff is the one thing I am most sure of, the one and only thing I have access to. So the challenge is to explain it (or explain it away). As you say, there's no place for it in a naturalist view of the world, and I agree.
> I just do not think that the experiences themselves are physical things, and on a purely naturalistic explanation of the universe experiences would not exist.
But they could be. Elsewhere in this thread, I mentioned computer science is effectively a branch of physics now, because we can connect computation with thermodynamics, and e.g. put lower bounds on amount of energy required to perform certain computation. Therefore, if you consider experiences to be "execution", some specific computations done by our brains, then they still are physical things. Might be tricky to point and prod at them in the structure of our brain, but physical concepts that are smeared over space or time are nothing new - think e.g. waves, whether EM waves or mechanical waves or virtual waves, think of the boiling soup they make out of their medium, and how e.g. Fourier transform can tease them all apart anyway.
> Therefore, if you consider experiences to be "execution", some specific computations done by our brains[...].
Which it seems to me to boild down to the assumption that intelligence and/or consciousness are computable. Which is a possibility, but we should keep in mind that we don't have any proof of this yet, only plausible-sounding arguments.
> if you consider experiences to be "execution"...
Why would anyone think that is true? The problem I find with responses like yours is that I think you haven't understood or fully appreciated what it is I'm pointing to that needs explaining. There's something real here that needs explaining or accounting for in a full theory, and an explanation like this doesn't even touch on it. In the full story of "what is experience", there is absolutely without doubt a computational side. But there is an aspect of experience, the 'felt'-ness of it, or the phenomenology, the qualia, that is not explained even in part by reference to computations or any other physical process.
There's just nothing like that, no precursors of it, to be found in the physical world. It's not the computational side of experiences, but rather the what-it's-like-ness of it.
Here's an example of it: what, given naturalism, explains the redness of seeing red? This is not a question about the wavelengths of light, or light hitting the retina, or processing in the brain that leads to the brain states that correspond to having that experience. This is a question about what it's like to see red -- the experiential side of the experience, as opposed to the physical causes of it. Why, given naturalism, would we think that anything experiences (first person perspective) anything at all?
Technically, software isn't exactly physical either, of course. It works with information contained in physical states, but isn't -technically- itself physical.
Arguably this can be demonstrated by moving it to a different physical representation (magnetic, optical, diode charges, dynamic memory cells; little endian, big endian; AMD, Intel, ARM, Turing Machine In Game Of Life, Minecraft Turing Machine) without affecting its behavior or functionality.
I don't think there's anything particularly mysterious about this kind of phenomenon, per-se.
You could grok the behavior of the software by poking at the hardware its running on for long enough; but it might be more useful to split the problem into separate layers that are easier to reason about. (Hence the need for reduction and emergence)
Hence my point about circuit bending. We're at the stage equivalent to that alien a) being able to electroshock the driver, and b) observe them getting out of car and functioning independently, therefore c) conclude that the driver is the thing controlling the car.
Not quite. What you prove by circuit bending is that you can alter behavior through physical means, no one's denying that. But the conclusion that because of that, then the physical means are also creating consciousness, that's not proven.
It's like assuming that the driver creates a spark in order to initiate combustion within the car, because the aliens haven't observed an instance of the car starting without the driver present.
necessity and sufficiency is insufficient (and not necessary) in biology. I've attended talks where the system was complex enough that something (a molecular factor) was sufficient, but not necessary! Pure logic isn't useful in biology because it's a feedback-controlled system with an enormous number of internal states.
Does it not illustrate that the person making the assertion either hasn't considered that their explanation is not necessarily exhaustive (in fact, as opposed to according to current theories within a popular, not entirely genuine/consistent in behavior at this point in time ideology), or would like you to believe that it is?
If there is a way to prove it is necessarily exhaustive, I would like to hear it.
Logic as applied to the real world is just beliefs too; using probability for the math is a way to account for uncertainty, instead of rounding everything up or down to impossible standards of "true" or "false".
> Logic as applied to the real world is just beliefs too
I disagree. For example: how can humans operating on scientific principles so consistently stack hundreds of "just" beliefs on top of each other to achieve things like landing things on the moon, as just one very old example?
I suspect there is more to it....I believe that all beliefs are not equal, and I'll go even further: some beliefs are true, and some beliefs are not true.
> using probability for the math is a way to account for uncertainty
That "account for" has a different meaning than "perfectly resolve" seems highly relevant.
> instead of rounding everything up or down to impossible standards of "true" or "false"
Of the two of us, who is rounding things up or down to an artificial truth?
> If in those cases, altering brain state creates/affects behavior and mental states, then there isn't really a place for a non-physical-stuff consciousness.
This does not follow. The altering of brain state affects behavior; from this we can deduce that there is a correlation between the two, and that there is a causal link between the two. We can't deduce from this that they're the same thing or that one is reducible to the other: this is illogical.
More generally, it is illogical to claim that brain states are the same as mental states (thoughts). There are several reasons for this. One is that reducing thoughts to brain states means a thought cannot be correct or incorrect. For example, one series of mental states leads to the thought "2+2=4"; another series leads to the thought "2+2=5". The correctness of the former and the wrongness of the latter refers only to the thought's content, not the physical brain state. If thoughts are nothing more than brain states, it's meaningless to say that one thought is correct -- that is to say, it's a thought that conforms to reality -- and that the other is incorrect. A particular state of neurons and chemicals cannot per se be incorrect or incorrect. If one thought is right (about reality) and another thought is wrong (not about reality), then there must be aspects of thought that are distinct from the physical state of the brain.
If it's meaningless to say that one thought is correct and another is incorrect, then of course nothing we think or say has any connection to reality. Hence the existence of this disagreement, along with the belief that one of us is right and the other wrong, presupposes that your position is wrong.
No amount of neurological study will undermine this argument. More generally, describing one aspect of reality in greater and greater detail doesn't gainsay those who claim there are other aspects. You can describe the inner workings of the brain in as much detail as you like -- it is nonetheless logically certain that human thought is not reducible to brain states, even though it obviously correlates with them.
> One is that reducing thoughts to brain states means a thought cannot be correct or incorrect. For example, one series of mental states leads to the thought "2+2=4"; another series leads to the thought "2+2=5". The correctness of the former and the wrongness of the latter refers only to the thought's content, not the physical brain state.
> If one thought is right (about reality) and another thought is wrong (not about reality), then there must be aspects of thought that are distinct from the physical state of the brain.
Of course there is. Computation. Observation. A correctness of a thought isn't a function of thought itself, it's a function of thought and reality. Correctness of a thought is not a physical label. It's not a state. It's something you evaluate, something you compute with respect to knowledge you observe.
The way I see it, you're confusing a thought with computed properties of it. There is no privileged notion of correctness and nature does not put XML tags with correctness score on neurons.
> A correctness of a thought isn't a function of thought itself, it's a function of thought and reality.
I agree with this, although I think it's more precise to say a thought is correct insofar as it conforms to reality.
> Correctness of a thought is not a physical label. It's not a state. It's something you evaluate, something you compute with respect to knowledge you observe.
This appears to be illogical. The correctness of my thought (that is to say, whether it conforms to reality) is one thing; my evaluation of its correctness is entirely different. Further, correctness must be a 'state', or property, of a thought: otherwise you undermine your own argument (see below).
> nature does not put XML tags with correctness score on neurons.
I agree with this. But this supports my argument. An arrangement of neurons (or anything physical) cannot be correct or incorrect. But a thought can be correct or incorrect (you must think that, because you must think you're right and I'm wrong about this disagreement). Therefore a thought cannot be reduced to an arrangement of neurons (or anything physical).
It's not plain correlation. It's long been experimentally demonstrated that you can circuit-bend[0] an animal or a human live, by poking in their brain[1]. If in those cases, altering brain state creates/affects behavior and mental states, then there isn't really a place for a non-physical-stuff consciousness. If it existed, it's demonstrably overridable by purely physical interventions, which implies you could just make a physical-stuff consciousness, at which point why postulate a non-material one?
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[0] - https://en.wikipedia.org/wiki/Circuit_bending
[1] - Then there's obviously alcohol, tobacco, and other drugs, that have a slower onset.