If we were to fabricate a human brain, would it be alive? Be conscious? Have free will?
Einstein would have referred to this as a thought experiment. I’m not asking if we have the technology to do this. I’m not even asking if we will ever have that technology. I’m just asking what it would be like if we could.
Here perhaps is another way to put what I am trying to ask: If we take a fresh human brain and start breaking it down into its constituent parts we see that it is organized as follows: There are the major brain components--frontal cortex, temporal cortex, cerebellum, corpus callosum, etc. These regions are in turn comprised of neuronal networks, which in turn are made up of neurons (of course), as well as various other types of supportive and connective tissue. The neurons, which are essentially just very sophisticated cells, are made up of cell parts such as a nucleus, axon, dendrites, membrane, etc. These in turn are made up of molecules--admittedly some very complex molecules, but molecules nevertheless, which in turn are made up of atoms. At the end of the day what we have is simply a large collection of atoms (which, of course, are made up of subatomic particles, etc., etc., but I think you get the point). And if you put a brain into a sealed container and just let it deteriorate, what you will have in time is nothing more or less than a soup of chemicals.
Sooo . . . theoretically we could take that chemical soup, rebuild the molecules, rebuild the cell parts, rebuild the cells and cell networks, and get back to a brain.
As I indicated, this sounds fantastically complicated and we humans just may not have the technological horsepower, if you will, ever to piece everything together. And even if we do, we would seem to be a very long way from being able to.
Because the human brain is so complex, maybe it would be better to think of something a bit simpler, such as the creation of a single-celled organism, like an amoeba. What if one were to inventory the parts of an amoeba, collect all of the component molecules and piece them together? Again, I’m talking theoretically, not practically. This “artificial” amoeba would be physically indistinguishable from a random amoeba that one might find on the street, or in your soup. No one questions whether the “natural” amoeba is living. Why would it be any different for the artificially created one? Since the natural and artificial amoebas are identical, atom for atom, whenever something happened, by reason of the laws of physics and chemistry, in the natural amoeba, the same would be happening in the artificial one at the same time. I’m talking biochemical reactions here that are admittedly extremely complicated but that could theoretically be broken down into a large number of simpler chemical and physical interactions. So if conditions led the natural amoeba to move in some direction, the same would be true for the artificial one. This could be said for all of each amoeba’s behavior--locomotion, ingestion, digestion, reproduction. If someone were to observe each side by side, it does not seem that the amoebas would be distinguishable.
Now, it’s a very long step from a one-celled organism (which we still aren’t close to creating artificially) to a human brain, but the differences are simply ones of size and organizational complexity. Both are just collections of chemicals, really.
My point? In my worldview life is simply an especially complex form of chemistry. We get fooled by the fact of consciousness (more to be said about this at a later time), but at the end of the day all biology, including human brains, is nothing other than chemicals.
So to answer the three questions that I posed originally: Yes. Yes, whatever that means. Nope.
© 2013 John M. Phillips