When I was young I tried to make machines out of Lego that were conscious. I would fit several cogs together and power them with water from the tap. When I grew up the machines got more complicated. I wrote computer programs that spoke and “reasoned”. One was a world in which characters worked out what to do to solve simple problems like hunger. Later, while studying artificial intelligence, cognition and psychology as a post grad I spent many happy hours in seminars considering the nature of consciousness and intelligence. Could a machine of sufficient complexity be conscious? Or would it always just be a simulation of true sentience? The discussions went in circles for lack of anything to ground them in.
My conviction now is that personhood is not reducible to matter and energy. Just because we have discovered so much by breaking things down into “simpler” units of these two components does not mean everything is so reducible. As the old story goes, it’s no good looking for a lost coin under a street lamp when it was dropped in a dark alley a long way away. Even if massive biological complexity were necessary for personhood (and it isn’t, take God for example) it need not be sufficient.
The bible says that personhood came first and then God spoke matter and energy into being. Further more, God then created persons like him to be conscious and aware. The issue is not whether or not God used an evolutionary process to form man but whether dusty, molecular Lego bricks was all he used to build us. My conviction is that something else is needed and the bible says that God imparted something more to us to make us living persons. Our personhood runs deeper than our physical biology. That, to me, seems a more reasonable view of things than that we are complicated machines powered ultimately by the sun.
PS – A corollary, which again seems self evident, would be that people matter, not because of what they can do, their function, but who they are: Persons made in the image of God. That means that if part of your machinery break down or don’t work properly, either your body or brain, you are still a person and still have value. Another related point is that love is real and eternal. God was and is eternally three persons in perfect relationship so we don’t just have personhood as foundational to reality but relationship as well.