| > 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 |
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.