Monday, May 20, 2019

Free will is indispensable for explaining our world

A podcast defends free will:
Unlike those who defend free will by giving up the idea that it requires alternative possibilities to choose from, Christian List retains this idea as central, resisting the tendency to defend free will by watering it down. He concedes that free will and its prerequisites — intentional agency, alternative possibilities, and causal control over our actions—cannot be found among the fundamental physical features of the natural world. But, he argues, that’s not where we should be looking. Free will is a “higher-level” phenomenon found at the level of psychology. It is like other phenomena that emerge from physical processes but are autonomous from them and not best understood in fundamental physical terms — like an ecosystem or the economy. When we discover it in its proper context, acknowledging that free will is real is not just scientifically respectable; it is indispensable for explaining our world.
List is correct about those last couple of points. Free will is not best understood in fundamental physical terms; acknowledging that it is real is not just scientifically respectable; and it is indispensable for explaining our world.

Even if you don't believe in free will, you still need to explain why some non-respectable concept is indispensable for explaining our world.

Jerry Coyne calls this incoherent:
In other word, some form of true libertarian free will arises mysteriously between the molecules that make up our brain and the behaviors that emanate from that brain.

Sadly, I cannot find anywhere in List’s spiel where he say how this emergent free will arises, or how it manages to defy the laws of physics. He uses weak analogies, like saying that while the “weather” arises from motions of molecules in the atmosphere, meterologists use models that abstract from the microphysical to the macrophysical and are indeterministic, giving probabilities of weather events. But that’s a bogus analogy, for the macro-“weather” is certainly consistent with, and arises from, lower-level phenomena. True, “rain” is an emergent property, but it is absolutely consistent with the laws of physics. List’s free will isn’t.
How is it that weather is any more consistent with the laws of physics than free will? There is no theory or experiment to substantiate this claim.

There is a long list of things that we cannot reduce to the motions of molecules. Weather is one, but many believe that is possible with sufficient info and computer resources. Consciousness is another, and no one knows how a computer would even start on that problem.

Coyne is right that no one can say how this emergent free will arises. I am not sure we can truly say how turbulence or phase transitions arise.

He is wrong to say free will (if it exists) must manage to defy the laws of physics. What laws are those? This is like people who say that the flying bumblebee defies the laws of physics.

Coyne elaborates on his opposition to libertarian free will, which he defines:
Libertarian free will means a form of free will independent of physical causality: a kind of free will that says, at any given moment when you face making a decision, you are not constrained to make a single decision. You could have done otherwise. ...
At a higher level of description, your decisions can be truly open. When you walk into a store and choose between Android and Apple, the outcome is not preordained. It really is on you.
If the outcome is not preordained, then it is a form of libertarian free will and not determinism. Period.
I agree with this, except that I am not sure what he means by "independent of physical causality". I believe in free will, I believe that I can choose between Android and Apple, and I also believe in physical causality. When I make that choice, it is a physical process, and my decision physically causes consequences.

Physical causality means that events are effected by what is inside the backward light cone. I include my mental processes as contributing to causality.

List argues:
One can have long debates about whether current AI systems are sufficiently advanced, but there is no conceptual reason why sophisticated AI systems could not qualify as bearers of free will. Much like corporate agents, which we also think should be held responsible for their actions, AI systems ideally should display a certain form of moral agency and not just rigid goal-seeking behavior in the interest of profit or whatever else their objective function might be. As we employ more and more AI systems in high-stakes settings, we would like those systems to make ethically acceptable decisions.
I may differ with him here. Those AI systems are nearly always deterministic. They may have ethical decision-making programmed in, but that is not free will.

There are those who think that the human mind is just a programmed Turing machine. There are others who believe that the mind is a window into the soul, separate from the body, and not constrained by physical law.

I think that there could be a middle ground, where the mind just functions according to material properties of the brain, but it is not a pre-programmed Turing machine either. It has consciousness, and the ability to make libertarian free choices.

Update: Coyne has a third rant against List, with a link to a technical 2014 List paper on the subject.

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