Would you ever actually be in a situation where you chose an action tied to an impossible counterfactual? Wouldn’t that represent a failure of Omega’s prediction?
It matters what you do when you are in an actually impossible counterfactual, because when earlier you decide what decision theory you’d be using in that counterfactual, you might yet not know that it is impossible, and so you need to precommit to act sensibly even in the situation that doesn’t actually exist (not that you would know that if you get in that situation). Seriously. And sometimes you take an action that determines the fact that you don’t exist, which you can easily obtain in a variation on Transparent Newcomb.
When you make the precommitment-to-business-as-usual conversion, you get a principle that decision theory shouldn’t care about whether the agent “actually exists”, and focus on what it knows instead.
All I’m saying is that when you actually make choices in reality, the counterfactual you end up using will happen. When a real Kant-Decision-Theory user makes choices, his favorite counterfactual will fail to actually occur.
Would you ever actually be in a situation where you chose an action tied to an impossible counterfactual? Wouldn’t that represent a failure of Omega’s prediction?
And since you always choose an action...
It matters what you do when you are in an actually impossible counterfactual, because when earlier you decide what decision theory you’d be using in that counterfactual, you might yet not know that it is impossible, and so you need to precommit to act sensibly even in the situation that doesn’t actually exist (not that you would know that if you get in that situation). Seriously. And sometimes you take an action that determines the fact that you don’t exist, which you can easily obtain in a variation on Transparent Newcomb.
When you make the precommitment-to-business-as-usual conversion, you get a principle that decision theory shouldn’t care about whether the agent “actually exists”, and focus on what it knows instead.
Yes. The actually impossible counterfactuals matter. All I’m saying is that the possible counterfactuals exist.
If you took such an action, wouldn’t you not exist? I request elaboration.
(You’ve probably misunderstood, I edited for clarity; will probably reply later, if that is not an actually impossible event.)
New reply: Yes, I agree.
All I’m saying is that when you actually make choices in reality, the counterfactual you end up using will happen. When a real Kant-Decision-Theory user makes choices, his favorite counterfactual will fail to actually occur.