David Lewis: 'Are we free to break the laws?'

David Lewis's compatibilist response to the Consequence Argument

[danwylie-sears]

You can't keep the past constant, while changing the laws of physics, unless the physics incorporates stuff like "grue and bleen". The past universe proceeded according to the laws of physics that we have, not according to some alternative.

My intuitions (as expressed in my comment on the previous video) are extremely compatibilist. But this version seems unsatisfactory. Seems to me, it's only in light of real-world physics that it makes sense to talk about what I _can_ do rather than what I _could_ do if physics were different. Real-world physics plus complete descriptions* of the state of the world give answers to questions about what would happen, including what I would do. Those descriptions can be of the actual state of the world, or of counterfactual states. You don't have to include other possible worlds in your ontology, in order to allow counterfactual descriptions of alternate scenarios. If I act according to my intention in a suitable range of such scenarios, doing various different things despite still being the same in suitable ways, then I can do those things.

*Such descriptions aren't possible under real-world physics as best I understand it, because of quantum weirdness. No-hidden-variables theorems and all that. But I don't claim to understand modern physics particularly well.

[joecampbell]

Describing it as a distinction between kinds of ability already leads to misunderstanding.Lehrer (1980) makes the point better, at least better than Lewis' commentators, which lead us to interpret the original in unfavorable ways. Consider: If the door is locked, I need not be able to unlock the door to be able to get out of the room. My ability hinges on the contingency of the door being locked. If someone else unlocks it - or if it magically becomes unlocked - I have the ability to leave. It need not be me that unlocks the door.