My personal opinion is that it's not just about brain quantity. I think being embedded in an environment is necessary for consciousness. My argument is that there is no such thing as unqualified consciousness -- you have to be conscious of something. You're not born aware of yourself, you spend the first few years of your life figuring out that you are embedded in this thing called a human body that, with considerable practice, you can exercise more-or-less direct control over. After more years you figure out that your body is further embedded in a world full of other things that you have only indirect (at best) control over, or no control at all. Only after all that can you draw a line between you and not-you and become aware of "your" existence.
I would not equate self-awareness with the feeling of being enclosed in some distinct thing called a human body that you can exercise control over. With the latter you are not just self-aware, you are also deconstructing experience into parts according to a particular dualistic approach (“that is my body, this is me”). Such deconstruction may not be required, and whether it is the only or even the best approach to qualifying own being is dubious (some might say you and your body are the same and implicitly treating “you” as “contained in your brain” is a fallacy—from the perspective of natural sciences a good illustration is probably how gut flora changes, non-brain organ transplantation, and such correlate with shifts in your personality).
> how gut flora changes, non-brain organ transplantation, and such correlate with shifts in your personality
Well, yeah, but so what? You can have shifts in your personality and still be you. You can be grumpy one day and happy another and still be you. And those changes can be cause by environmental changes far less radical than organ transplants.
The one thing you cannot swap out and still remain you is your brain.
> You can also not swap out your body and remain yourself.
Why not? Even taking technological limitations into account, there is almost no part of your body that can't be swapped out even today. People have artificial limbs, artificial hearts, artificial ears. They get lung transplants, kidney transplants, face transplants. Give the technology a few more centuries and I don't see any reason why a complete body swap-out should not be possible.
> it is not an easy question to answer
Indeed. But most people would agree that you can get an organ transplant or an artificial limb or a hearing aid or wear glasses -- or any combination of the above -- and still be you. Not so for a brain transplant.
> But most people would agree that you can get an organ transplant or an artificial limb or a hearing aid or wear glasses -- or any combination of the above -- and still be you. Not so for a brain transplant.
I do not think that is relevant in any way. Most people also believe in God; that does not make it a compelling claim.
But sensory deprivation chambers are both known to make people unconscious, don't completely remove all sensation, and still induce hallucinations reliably. The conscious entity has to be conscious of something, and if there's nothing it will create something to be conscious of.
Please, educate us. Why is it garbage? To me and perhaps others, this makes intuitive sense. Why shouldn't it take several years for an intelligence to build self-knowledge before it can develop what we call consciousness? Why shouldn't consciousness be emergent, as an intelligence slowly understands that it is limited to a physical form?
Why shouldn't it be baked into the neural structure that has evolved over the past half billion years? Why should it require years after birth to manifest?
