[fasterik]

This is similar to David Lewis's modal realism, which says that every possible world is real:

https://en.wikipedia.org/wiki/Modal_realism

There isn't really much of a connection between this and Bostrom's simulation argument. The simulation argument is about calculating the probability that we live in a simulated universe based on certain assumptions about human behavior and technological development. Bostrom's argument doesn't make any metaphysical claims other than assuming that consciousness is substrate independent.

I don't buy into metaphysical theories that claim to deduce the existence of worlds outside our own based on armchair reasoning. We know that the physical universe exists and we can explain everything that we experience in terms of quantum field theory and general relativity. Any theory that wants to challenge this view of the world needs to modify those existing theories, or design an experiment that shows why they aren't adequate to explain reality.

[pringk02]

Modal Realism was the inspiration for the somewhat infamous, slightly tongue-in-cheek "Possible Girls" paper where Neil Sinhababu argues that people across different modal realities can fall in love with each other (and that explains imaginary relationships)

https://philpapers.org/archive/SINPG

It's a fun read

[TheBlight]

>we can explain everything that we experience in terms of quantum field theory and general relativity.

Dark matter would like a word.

[fasterik]

As I understand it, the major candidates for dark matter are new elementary particles, so they would still fall under quantum field theory.

Of course, there is always the possibility that another revolution in physics happens, but even then our current theories will still be valid in most domains, in the same way that Newtonian mechanics is still valid in most domains.

[ben_w]

> we can explain everything that we experience in terms of quantum field theory and general relativity

Everything we experience, except experience itself. Conscious/qualia/whatever is still… well, none but God knows what it is, and I have no evidence for the existence of any god let alone that one.

[fasterik]

That's because consciousness is an emergent phenomenon, not part of fundamental physics. Every atom in your brain behaves according to the laws of particle physics, and somehow consciousness emerges out of that. Our theories of neuroscience aren't developed enough to explain it yet, but there isn't any reason to believe that there is something magical or non-physical going on.

[iosystem]

How do we know consciousness is real, and we're not just the same as robots or a tv series? Couldn't every moment throughout the universe have been encoded in every atom before the Big Bang?

[mcronce]

That's certainly possible, but it doesn't make your experiences any less real

[dilyevsky]

It certainly does because in this case there is no “you”

[ben_w]

"There is a thought now" has real experiences without anything we would normally want to call a real experiencer.

[mcronce]

And yet here you are reading that comment, writing this one... And those experiences are real.

[msarchet]

You is a very loaded word here.

[Ycombigatorz]

How do you know that when you touch a chair that that sensation is real?

[msarchet]

https://en.wikipedia.org/wiki/Qualia[1] - is what you are now describing mixed with a little bit of Maxwell's Demon[2] - something is intercepting between you and a true experience.

Real, in the way I believe you are trying to express, is a complicated topic.

1 - https://en.wikipedia.org/wiki/Qualia 2 - https://en.wikipedia.org/wiki/Maxwell%27s_demon

[ben_w]

I'm nit picking here, but I think you meant Cartesian demon?

[perfmode]

Why believe consciousness arises from matter?

Versus matter arising from consciousness?

[satvikpendem]

Because we can change brain states (ie, manipulating a material object) to go from conscious to unconscious, which is strong evidence for the former. What evidence is there for the latter?

[placebo]

This is evidence that self-conscious beings can stop being self-conscious or that the content of what they are conscious of can change when the stuff that enables self-consciousness to occur is manipulated. It does not prove that consciousness is an emergent phenomena. Suggestions that consciousness is prior to physicalism (and in general prior to the whole division into subjective and objective realities made by a rational self-conscious agent) are not something new and are worth exploring.

[paulrudy]

> consciousness is an emergent phenomenon That's a theory that has yet to be tested, not a certainty.

<digression>

> Every atom in your brain behaves according to the laws of particle physics...

These are assumptions. They're very plausible and useful ones. They may turn out to be absolutely correct, but it's still worth noting that they are theories.

"Every atom behaves..." so far, so good, yes it does.

"...according to the laws of particle physics"-- presumably yes, with this caveat: The existence of a complete set of inviolable "laws" that explain _all_ physical behavior is an article of faith. It's a plausible potential outcome of the extremely practical process of collective scientific inquiry that so far seems to hold up, but still-- the concept of a set of laws as programs and constraints for absolutely all physical phenomena is fundamentally a philosophy. It has proven to be extremely useful, but it's not a proven or even probable fact. It's a powerful axiom.

</digression>

> ...and somehow consciousness emerges out of that.

Back to the assumption that consciousness is a phenomenon that emerges from the physical activity of a brain:

Is a (functional) brain both necessary and sufficient for consciousness to "emerge"? I don't know, I'm just a person interested in this stuff, but I think it's an important question without a definite answer.

We tend to assume that having a brain is a necessary requirement for consciousness, but testing for consciousness (not to be confused with mere rationality) is difficult, as far as I know. I can't prove that a stone, plant, or region of spacetime has no consciousness.

Even if we came up with a test for "consciousness", and that this test _did_ prove that a brain (or a similarly complex network) is necessary for consciousness to appear, there is still the issue of whether the brain is sufficient. How would we know?

Whatever it is that we call consciousness may emerge from the complex physical phenomena of brain activity, as you said. Or the brain may be a catalyst for the phenomena we label consciousness. Or a brain (or human body) may only be a prerequisite for us, with our current capacities, to be able to observe the experience we have come to label "consciousness".

"Light" used to mean only the visible spectrum, until we understood there was more to it: Light went beyond the limits of what we had up til then used to recognize its existence, and indeed it occurred even in what we had called "darkness", and blue things didn't contain blueness in and of themselves, nor were blue things producing blue light.

I'm not advocating for any particular alternate theory, or proposing that consciousness operates outside of known physical constraints, I'm just a stickler for reminding ourselves what concepts are articles of faith, even in science itself

[fasterik]

I don't think "article of faith" is the right phrase. For every possible hypothesis, we attach a prior probability and then we update those probabilities when new evidence comes in. If accepting a given hypothesis would require changing a lot of other hypotheses that we have high confidence in, then we should attach a low prior probability to it. I don't have to take it on faith that a low probability hypothesis is false; the default position is to assume that it is false until compelling evidence to the contrary appears.

For example, I can hypothesize that a fifth fundamental force is needed to explain consciousness, but then I need to modify the standard model of particle physics to account for new interactions. I have a high confidence that the standard model is correct in the domains relevant to the evolution of life on Earth, namely chemistry and biology. So my default assumption is that we don't need to introduce new laws of physics to explain consciousness.

>Is a (functional) brain both necessary and sufficient for consciousness to "emerge"?

I think you misread my post as implying that a brain is required for consciousness. Our baseline for talking about consciousness is consciousness in humans, and all of the medical evidence suggests that human consciousness is associated with brain activity. But I see no reason to believe that something made out of silicon or other non-organic materials couldn't be conscious if it implemented the same kind of processes that we find in the brain.