What a weird word. It sounds like a ghost, materializing in front of me. And it is sort of like a ghost, one that has mysteriously taken over the minds of many intelligent people.
Because they believe in materialism, these smart people don’t believe in ghosts. Especially the ghost in the machine. The problem is there is no way for the ghost to interact with the machine. This is known as the “mind-body interaction problem”. The great thing about materialism is at least that theory doesn’t have an interaction problem. Any material thing can interact with any other material thing.
Yet there is a deep irony. Let’s explore the idea of materialism to see why.
Materialism is the idea that reality only consists of matter. The idea has a large fan base among the sciences because it means the sciences can explain all of reality, sort of like religions used to claim. But what is matter?
Therein lies the rub. The definition of matter has changed over time. So, while materialism may explain all of reality, our concept of materialism certainly doesn’t, or certainly didn’t.
An Old Theory
In the beginning, the ancient Greek philosopher Democritus said reality only consisted of three things: atoms, the universe, and the void (empty space around the atoms). Everything else: trees, flowers, colors, music, happiness, humans, and Democritus, did not exist. Rather, everything else was a bunch of atoms colliding with each other in just the right way. The interaction was easy to explain.
There is a simplistic elegance to the idea. Everyone has at one time or another in their life hit one rock with another rock. The rocks bounce off each other and hit other rocks. With enough rocks, who knows what patterns can emerge? If we squint just right, some of the patterns in the bouncing look like bunnies. Given enough imagination, a really progressive thinker can extrapolate all of reality to many tiny little rocks colliding. And that’s how we got the original concept of materialism.
There are a few difficulties with the idea. Lucretius, a Roman materialist philosopher, valiantly struggled with the limits imposed by materialism. There is only so much one can do with rocks hitting each other. For one thing, rocks don’t pull each other. Except for magnets. Magnets pull each other. Magnets flummoxed Lucretius. The best he could come up with is that the force of attraction was caused by a very complex vacuum effect. Another problem was the spherical earth. Without a force of attraction, the people on the bottom of the earth would fall off. This was absurd, so Lucretius maintained that the earth was flat.
Despite all the difficulties, the materialism of Democritus became quite influential. It is where we get our atomic theory as well as the theory of evolution.
Here Comes Newton
Yet not all was well in materialism land. Along came Newton who said there was an attractive force in the universe called gravity. What’s more, this force permeates the entire universe such that a particle at one end of the universe attracts a particle at the other end. There’s absolutely no way this could be explained by rocks hitting each other. The interaction problem of gravity demolished materialism. And with that, no one believed in materialism ever again.
Except they did. Many smart people continued to believe adamantly in materialism, despite the fact Newton conclusively disproved the theory. What to do? If you can’t beat them, rename them. Materialists discreetly dumped the theory of gravity into the big vat of materialism and swished it around so no one would notice.
The same thing happened with field effects. Not only do two mega-distant particles attract each other, but particles also don’t even have the good manners to collide anymore. Another interaction problem. Particles instead hover in their own safe spaces far away from any other particles. If any particles try to get near, their force fields push them apart again. So, most of what we see around us is a bunch of empty air. Rocks don’t even collide these days.
What About Quantum Physics?
Weirder still with quantum physics, spooky action at a distance, entanglement, and the like. More interaction problems.
But each time our valiant materialism enforcers, instead of acknowledging the error of their ways, took out their large materialism stamps and stamped a fresh “materialism” on the latest refutation of the theory.
However, when it comes to the soul, suddenly tactics change — no more rubber stamping “materialism” to cover up interaction problems. There is an interaction problem since the brain cannot explain the mind. For some reason, this interaction problem is a bridge too far for materialists. Instead of saying the mind’s interaction with the brain is another aspect of materialism, smart people say the mind doesn’t exist.
What is the moral we can draw from this story? The interaction problem is not specific to the mind and body. Interaction problems are everywhere we look in physics. The only reason we don’t notice them is that they’ve been rubber-stamped as acceptable. So, if interaction problems are everywhere in physics, the mind-body interaction problem is not a reason to ignore the mind as a scientific theory.