Motivation
I received quite a lot of counter arguments and criticism for my article “Free Will Does not Exist” [1], where I describe what I observe is current knowledge about how the brain works, and thus I conclude that free will does not exist.
One of the counter arguments was that as the brain is very complex, that neuroscience does not know yet how it works, and that it may never know because the levels of higher order complexity may be too much for humans to understand, then free will must exist, but that it is too complex to understand.
Because I do not agree with that logic, I came up with a principle that I will call “The Principle of Physical Explanation”.
Principle
If higher order complexity can be reduced to simpler lower order physical phenomena, then higher order complexity must also be bound by the laws of physical phenomena. Regardless whether they are understood or not.
Rationale
When I was going through rough times in my life, my sister suggested me to talk to a priest. He told me God must exist because we don’t understand nor know things outside of the observable universe or our current knowledge of physical laws. That is where God exists.
It is a similar argument as “X must exist because above a certain complexity level we don’t know or can’t know what happens”.
I think it has to do with the “non falsifiability” problem [2], but if every time we advance in some knowledge we encounter physical explanations, it must be, then, that all higher order levels must also have physical explanations. Especially if we agree that higher order complexity is the product of lower order simplicity.
Note the above is not an argument against culture, religion, christianity, ethics, morality, the law, or anything of the sort. I am very much in favor of those things regardless of their genesis.
It’s just about the nature of things.
Examples
Weather
The weather is very difficult to predict beyond a few weeks. My principle, rather than saying “we know how the weather will be in eight weeks”, it says we can know how the weather will be week by week for eight weeks. Therefore, for the whole eight weeks it was all about underlying physical phenomena as that is the method we used to predict each week.
Quantum Wave Function
When I learned about the probabilistic nature of reality at the quantum level, I thought it was very interesting and I even thought that it proved free will existed, as there is a point where a mechanistic cause and effect chain was broken. However, if we agree that probability at the quantum level is a physical feature, then free will disappears again.
If we consider the unknowable things as black boxes, we could consider a quantum state as a black box where we will never know for sure all the states at the same time. However, there is a probability function we use as a mathematical tool to manage that black box. That could be considered a non supernatural solution.
Beyond the Observable Universe
In the case of the universe, beyond the observable universe may be considered a black box. However, if we can move toward the cosmological horizon, segment by segment, we can know how the underlying physics of each segment works like we know the solar system for example.
This means we can eternally move toward the cosmological horizon and discover, segment by segment, that all work according to the laws of physics. The cosmological horizon, thus the black box, indeed, will be constantly moving further away as well. Talk about moving the goalposts!
Complexity of the Brain
In the case of the complexity of the brain, we may never figure out how all the parts work together to create our consciousness and experience of reality, but we can know, part by part, how they work individually and observe that all respond to physics and chemistry.
So, the principle is that if we can always discover that each piece of reality is a physical reality, then all of reality must be a physical reality, even if we may never know all of it.
References
[1] Free Will Does not Exist – by Donald McIntyre: https://etherplan.com/2020/11/15/free-will-does-not-exist/13610/
[2] Karl Popper Theory of Falsification – by Saul Mcleod – Simply Psychology: https://www.simplypsychology.org/Karl-Popper.html
