Free will is like temperature
Free will is like temperature: a useful tool for analyzing the behavior of certain systems which are too big and complicated to model in exact detail.
If you know the positions and velocities of every atom in a box of gas, then with enough work you can predict its future to arbitrary precision; does the gas “have a temperature”? Irrelevant! Technically yes, I guess, but it’s sort of an epiphenomenon, screened off from reality by your exact knowledge of the initial conditions and your willingness to throw processor cycles at your simulation. But if you’re less-than-perfectly omniscient, it might be more convenient to consider the box as having a “temperature” and model it more abstractly.
Substitute “person+environment”/”free will” for “box of gas”/”temperature” and that’s all still true.
Maybe your box of gas is supercooled; if you know the initial conditions exactly, you can predict exactly when and where the first large droplet will nucleate, but if your vision of the box is even a little bit fuzzy, you’ll instead need to use your understanding of “temperature” to build a probability distribution over when it will condense / whether it will be on a wall or in the gas’s bulk / …
Maybe Alice has a nasty fight with her spouse; if you know the initial conditions exactly, you can predict exactly what she’ll do, but if your vision of her is even a little bit fuzzy, you’ll instead need to use your understanding of her “free will” to build a probability distribution over whether she goes to the lawyer’s office / gun cabinet / …
(Tongue partly-but-not-entirely in cheek: if you painstakingly prepare a second box of gas with the exact same initial conditions as the first, it will have exactly the same temperature; if you painstakingly prepare a second person with the exact same initial conditions as the first, they will have exactly the same free will.)
(I think some version of this idea is in the water supply, but I’ve never seen somebody point directly at it. Claude suggests it’s very like Dennett’s “intentional stance” or Carroll’s “poetic naturalism”; upon inspection, I agree, but still view this as worth posting.)
Lately I’ve been thinking about proof-based agents: agents that search for proofs in Peano Arithmetic of the consequences of their actions, and decide based on that.
I think when you formulate them right (which would be very different from the last attempt), they have a kind of “free will” that comes from this kind of underspecification.
Specifically: the proof system used to derive stuff like “if I take action A, then the environment will be in state S” cannot derive stuff like “I take action A”.
The model of the agent where I think this works out is it is doing a random proof search. Or a pseudorandom proof search, and “I take action A” means “I take action A regardless of the seed for the random number generator”. That is, the proofs are actually about an ensemble of agents with different RNG seeds.
Since the proof system can’t prove its consistency, it can’t prove that all proof searches will come up with the same result.
This incompleteness about the antecedents of our counterfactuals looks a bit like free will, but it requires considering this ensemble of agents, where we specify they’re doing a proof search but leave out the “microscopic” detail of the RNG seed.
This is in contast to functional decision theory, where we work with a complete specification of the agent, and thus need counterpossible implications, where the antecedent is provably false.
I’m hoping to work out the details and post more about it soon. For now you can believe me or not that this is a coherent theory.
But yeah, I think underspecifying “microscopic” details in a “macroscopic” description is where you get something like free will.
People always say randomness doesn’t help with free will, but it seems to me there’s this weird middle path, where your actions are not determined (in PA), but still not arbitrary (becaue they’re determined in PA+consistency of PA).
An action is later in logical time than the prior considerations that determine it. And the prior considerations shouldn’t always be consequentialist with respect to the resulting action (they could be unrelated background facts, or consequentialist with respect to some other decision, perhaps made by a different agent, which is important for acausal coordination). I think this is conceptually cleaner than only considering consequentialist arguments.
In general, you can’t insist on waiting for a prior consideration to settle before making a decision, since it can take too long (or it can even directly wait for your own action before giving its answer, making it impossible to out-wait it). So there needs to be a timeout. Proof length bounded provability ia one way of doing it, where you wrap all prior considerations in provability-within-length-k boxes. But the issue here is that you might want to care about the proof being used, rather than be OK with any old sufficiently short proof. This is similar to how you might want to care which prior considerations to use, rather than go with all possible consequentialist considerations with respect to your action.
This is true for most concepts.
It’s an especially useful frame for free will, moreso than for temperature I think. Free will’s subjectivity is relevant because (unlike for temperature) humans can in fact outgrow its use in some contexts.
For a physical calculator and a fact of arithmetic it produces/witnesses, it’s the abstract arithmetic that’s the relevant thing, rather than the physical calculator. An interpretation of data can be more important than the data, or than a causal process that produced the data.
How are you defining free will?
Are there any possible facts that could render free will illusory, eg. determinism?
Is there any possible configuration of physics where free will us more than a stance or metaphor?
I’m defining free will as, eh, you know, that kind of thing that people are gesturing at when they talk about free will. (Or, equivalently, no, I’m not defining it.) Or, extensional definition: it’s the capacity-for-choice-flavored thing that humans have, dogs and AIs kind of have, flies maybe have tiny glimmers of, and plants and rocks don’t.
I assert that determinism renders free will exactly as illusory as it renders temperature!
I… don’t know how I would tell whether a given universe had that property. Same if you replace “free will” with “temperature”.
People mean different things by “free will”, which is why the question is worthy asking.
Different definitions of free will require freedom from different things. Much of the debate centres on Libertarian free will, which requires freedom from complete causal determinism (and therefore, freedom from inevitability). Libertarian free will requires leeway, or multiple possibilities at a moment in time. That’s often expressed as being able to act differently if the history if the universe were rewound. Compatibilist definitions of free will only require freedom from compulsion, and allow free will to exist in a deterministic universe . A third set of concerns is free will is a form of conscious control,top down control or initiation of action by an inner self.
Libertarian and compatibilist free will aren’t opposites. Compatibilism says you act freely and responsibly when you have a normally functioning brain , and lack external conclusion from another agent. Libertarians don’t have to reject the compatibilist criteria—it would be rather absurd that you can be free while being compelled—they just have to regard them as insufficient, because the further criterion of leeway is lacking.
Libertarian free will has sub-varieties.
One is “contra causal” free will, which requires freedom from physics, on the assumption that physics is deterministic. This is often connected with the idea of a supernatural soul, that is able to override the physics of the brain. In contrast, naturalistic libertarians seek to find free will within physics, by rejecting physical determinism; they regard indeterminism as a necessary (but perhaps not sufficient) condition of free will.
Another is that free will requires freedom from any limitation whatsoever …but that is the definition of omnipotence. It is a straw-man position which is not adopted by actual believers in free will: believers in naturalistic free will accept that they are constrained by the laws of nature. Believers in supernatural free will believe that God alone is ominipotent
The question of whether physics allows free will does not depend on physics or neurology alone: it also depends on how free will is conceptualised. It is neither a purely scientific nor a purely philosophical issue.
But whether humans have it is contentious. ..at least under the Libertarian definition.
It you think humans definitely have it , you’re siding with the compatiblist definition. Which in turn means the definition, not a discovery about the world, is doing most of the work.
Half of the talk about free will is people saying it doesn’t exist.
I’m not a physicist but aren’t such things inherently unpredictable?
At any given moment what you will think next in your brain is random, and there is a very small chance that you may be thinking literally anything at all and there is even a chance that your brain vanishes into thin air in any given moment.
They might be “chaotic” in that tiny errors rapidly amplify into huge ones; but for any finite amount of error you consider tolerable in the simulation, there still exists some finite level of precision in specifying the initial conditions to achieve that error rate. So, practically speaking unpredictable yes, theoretically unpredictable no.
Oh, or were you talking about quantum non-determinism? If so: I bet there is a deterministic physics very much like “ours minus quantum” ~= “the way people thought the world worked in 1890″, which could support human civilization as it existed when people were talking about free will a thousand years ago. In which case, people would be talking about free will in the way they do in our universe, with the same intuitions about it, and they wouldn’t have QM to fall back on to break free of determinism.
In which case, I don’t think QM can be relevant to any sort of discussion of free will that people were having before the 20th century.
(I also subscribe to an interpretation of quantum mechanics that contains no non-determinism, but I expect that to be a harder sell than the “people would talk the same way about free will even with deterministic physics” argument.)