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.)
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.
(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.)