Nothing new, I’m sure, but I do wonder…
The human brain is made of matter. Atoms, sub-atomic particles, quarks, etc. Perhaps we can define thought, consciousness, as a particular pattern of atomic movement. This is not to say that thought is this particular movement, only that it emerges when such movement is present. This would be compatible with a completely deterministic view of the world (and would also be compatible with Christianity and free will, depending on how they are understood).
This leads to some questions. (Well, it leads to many questions, but these are the ones that come to my mind most prominently at the moment).
Firstly, can consciousness exist without physical matter? A believer in an after life might be tempted to quickly answer yes. But what Heavenly religious figure ever claimed that the after life would be separated from physical manifestations? We can already claim that our consciousness isn’t merely physical; that is, it doesn’t exist just because a bunch of atoms exist. It emerges from the particular positions and movements of many billions of atoms. It’s like a marching band forming shapes and patterns on a football field; no individual performer creates the pattern; it is created by the collection of them, each in a certain position. The pattern is created by their positions and movements relative to one another. (That’s actually a strange analogy, however, since patterns and a sense of order in such assemblies actually emerge from the same thing: our consciousness. We perceive the order. That’s not to say that the order isn’t really there; it is. But there’s nothing special about it relative to anything else until it’s perceived by a consciousness.) Just as we can’t have a marching band formation without a certain number of members of a marching band, perhaps we can’t have consciousness without the necessary amount of atoms (and atoms to stimulate those atoms) existing in the proper order.
Does the nature of the physical matter matter? If I represented each atom in the brain with a stone on an infinite concrete floor, and I represented its position in 3D space by moving stones around on a 1D line (like a Turing Machine), I could certainly represent any possible thought process (assuming determinism). Would such a representation be just as conscious, because it was worked through with physical means? What if I had an infinite amount of time and just thought about all the steps I would take to do so. Could I create a new consciousness from my consciousness? (Our consciousnesses would still be completely separate entities; I’m not claiming our conscious experiences would meld into one or anything.) Or does it all have to be directly done with only atoms?
What if your brain existed in two places? That is, what if there was a brain completely like yours, but on another planet. It perceived the exact same things as you. Assuming determinism, we can even say it would make exactly the same decisions you would, and even think exactly the same thoughts. Would that other you be you? I reckon so! Different atoms, but exact same emergent property.
OK, what if it was a copy of you as you are now, but from now on would have different perceptions, different experiences. A clone, essentially. Now you are not the same emergent property. But which one would you be?
What if you died, but I saved the state of your mind right before you died and recreated you. Would that be you? Or a new person just like you? You might argue it would be a new person, because the atoms would all be different. But would that really matter so much?
It’s strange, because even now, our brain is flowing; atoms are moving around, the physical manifestation of your current being is constantly changing. Our brains need food and oxygen to continue functioning (e.g. hold your breath long enough and you’ll pass out; hold it even longer and you’ll die; the brains needs certain particles in oxygen atoms to work).
Are you the same you you were yesterday? If not, what happened to him?
One thing that changes constantly, that we can’t function without, is memory. But there are quite a few philosophical problems we can get when fooling around with memory. Are you morally responsible for crimes you committed if you can’t remember them? Would you even really be you if you forgot too many memories, or if you were implanted with new false ones? Are memories of some sort an essential ingredient to consciousness? In other words, is any sort of consciousness possible without memory?
If we continue being the same person even though the physical atoms in our brain change, and our memories change, why wouldn’t you be the same person if you mind had a new physical manifestation elsewhere in the universe?