= 27d567bc2d48d9f40e9ccc20ea370b15)
You said "you shouldn't smoke", which is a decision-theoretical claim, not a specification. It's consistent with EDT, but not CDT.
No it isn't, it's a statement about the universe: If you smoke, you'll get lesions. It's written into the specification of the universe; what decision theory you use doesn't change the characteristics of the universe.
In other words, you're denying the exact thing that CDT asserts.
No. You don't get to specify a universe without the kind of causality that the kind of CDT we use in our universe depends on, and then claim that this says something significant about decision theory. Causality in our hypothetical works differently.
Which is what a counterfactual is.
No it isn't.
Whatever your theory is, it is denying core claims that CDT makes, so you're denying CDT (and implicitly assuming EDT as the method for making decisions, your arguments literally map directly onto EDT arguments).
No it isn't. In terms of CDT, we can say that smoking causes the gene; this isn't wrong, because, according to the universe, anybody who smokes has the gene; if they didn't, they do now, because the correlation is guaranteed by the laws of the universe. No matter how much work you prepared to ensure you didn't have the gene in advance of smoking, the law of the universe says you have it now. No matter how many tests you ran, they were all wrong.
It may seem unintuitive and bizarre, because our own universe doesn't behave this way - but when you find yourself in an alien universe, stomping your foot and insisting that the laws of physics should behave the way you're used to them behaving is a fast way to die. Once you introduce a perfect predictor, the universe must bend to ensure the predictions work out.
You don't get to specify a universe without the kind of causality that the kind of CDT we use in our universe depends on, and then claim that this says something significant about decision theory.
What kind of causality is this, given that you assert that the correct thing to do in smoking lesions is refrain from smoking, and smoking lesions is one of the standard things where CDT says to smoke?
"A causes B, therefore B causes A" is a fallacy no matter what arguments you put forward.
In terms of CDT, we can say that smoking causes the gene
CDT asserts the opposite, and so if you claim this then you disagree with CDT.
You don't understand what counterfactuals are.
This implicitly assumes EDT.
No it doesn't. It assumes a "perfect predictor" is what it is. I don't give a damn about evidence - we're specifying properties of a universe here.
But that's not what CDT counterfactuals do.
CDT assumes causality makes sense in the universe. Your hypotheticals don't take place in a universe with the kind of causality causal decision theory depends upon.
You cut off previous nodes. As the choice to smoke doesn't causally affect the gene, smoking doesn't counterfactually contradict the prediction.
In the case of a perfect predictor, yes, smoking specifies which gene you have. You don't get to say "Everybody who smokes has this gene" as a property of the universe, and then pretend to be an exception to a property of the universe because you have a bizarre and magical agency that gets to bypass properties of the universe. You're a part of the universe; if the universe has a law (which it does, in our hypotheticals), the law applies to you, too.
We have a perfect predictor. We do something the perfect predictor predicted we wouldn't. There is a contradiction there, in case you didn't notice; either it's not, in fact, the perfect predictor we specified, or we didn't do the thing. One or the other. And our hypothetical universe is constructed such that the perfect predictor is a perfect predictor; therefore, we don't get to violate its predictions.
No it doesn't. It assumes a "perfect predictor" is what it is. I don't give a damn about evidence - we're specifying properties of a universe here.
You said "you shouldn't smoke", which is a decision-theoretical claim, not a specification. It's consistent with EDT, but not CDT.
You don't get to say "Everybody who smokes has this gene" as a property of the universe, and then pretend to be an exception to a property of the universe because you have a bizarre and magical agency that gets to bypass properties of the universe.
In other words, you're denying the exact thing that CDT asserts.
There is a contradiction there
Which is what a counterfactual is.
Whatever your theory is, it is denying core claims that CDT makes, so you're denying CDT (and implicitly assuming EDT as the method for making decisions, your arguments literally map directly onto EDT arguments).
I may be misunderstanding something, but isn't the standard LW position on smoking to smoke even if the gene's correlation to smoking and cancer is 1?
If the mutual correlation to both is 1, you will smoke if and only if you have the gene, and you will have the gene if and only if you smoke, and in which case you shouldn't smoke. At the point at which the gene is a perfect predictor, if you have a genetic test and you don't have the gene, and then smoke - then the genetic test produced a false negative. Perfect predictors necessarily make a mess of causality.
you will smoke if and only if you have the gene, and you will have the gene if and only if you smoke, and in which case you shouldn't smoke
This implicitly assumes EDT.
At the point at which the gene is a perfect predictor, if you have a genetic test and you don't have the gene, and then smoke
But that's not what CDT counterfactuals do. You cut off previous nodes. As the choice to smoke doesn't causally affect the gene, smoking doesn't counterfactually contradict the prediction. If you would actually smoke, then yes, but counterfactuals don't imply there's any chance of it happening in reality.
I'm denying CDT, but it is a mistake to equate CDT with Eliezer's opinion anyway. CDT says you should two-box in Newcomb; Eliezer says you should one-box (and he is right about that.)
More specifically: you assert that in Newcomb, you cause Omega's prediction. That's wrong. Omega's prediction is over and done with, a historical fact. Nothing you can do will change that prediction.
Instead, it is true that "Thinking AS THOUGH I could change Omega's prediction will get good results, because I will choose to take one-box, and it will turn out that Omega predicted that."
It is equally true that "Thinking AS THOUGH I could change the lesion will get good results, because I will choose not to smoke, and it will turn out that I did not have the lesion."
In both cases your real causality is zero. In both cases thinking as though you can cause something has good results.
I'm not equating them. TDT is CDT with some additional claims about causality for logical uncertainties.
You deny those claims, but causality doesn't matter to you anyway, because you deny CDT.
"Counterfactual probability", in the way you mean it here, should not play a role in decisions where your decision is an effect of something else without taking that thing into account.
In other words, the counterfactual you are talking about is this: "If I could change the decision without the lesion changing, the probability of having the lesion is the same."
That's true, but entirely irrelevant to any reasonable decision, because the decision cannot be different without the lesion being different.
So all you're doing is denying CDT and asserting EDT is the only reasonable theory, like I thought.
When you say, "this ignores causality," do you intend to make the opposite statements?
Do you think that if a lesion has a 100% chance to cause you to decide to smoke, and you do not decide to smoke, you might have the lesion anyway?
Do you think that if a lesion has a 100% chance to cause you to decide to smoke, and you do not decide to smoke, you might have the lesion anyway?
No. But the counterfactual probability of having the lesion given that you smoke is identical to the counterfactual probability given that you don't smoke. This follows directly from the meaning of counterfactual, and you claimed to know what they are. Are you just arguing against the idea of counterfactual probability playing a role in decisions?
So you're saying that if Omega predicts from your thought process, you choose one-boxing or not smoking, but if Omega predicts directly from the lesion, you choose two-boxing or smoking?
I don't see how that is relevant. The description I gave above still applies. If you choose one-boxing / not smoking, it turns out that you get the million and didn't have the lesion. If you choose two-boxing / smoking, it turns out that you don't get the million, and you had the lesion. This is true whether you followed the rule you suggest or any other. So if TDT recommends smoking when Omega predicts from the lesion, then TDT gives the wrong answer in that case.
If you choose one-boxing / not smoking, it turns out that you get the million and didn't have the lesion. If you choose two-boxing / smoking, it turns out that you don't get the million, and you had the lesion.
Well as I said above, this ignores causality. Of course if you ignore causality, you'll get the EDT answers.
And if you define the right answer as the EDT answer, then whenever it differs from another decision theory you'll think the other theory gets the wrong answer.
None of this is particularly interesting, and I already made these points above.
In the lesion case, I am assuming that the lesion has 100% chance of causing you to make a certain decision. If that is not assumed, we are not discussing the situation I am talking about.
So the causal process is like this:
- Lesion exists.
- Lesion causes certain thought process (e.g. "I really, really, want to smoke. And according to TDT, I should smoke, because smoking doesn't cause cancer. So I think I will.")
- Thought process causes smoking and lesion causes cancer.
I just simulated the lesion process by thinking about it. Omega does the same thing; the details of 2 are irrelevant, as long as we know that the lesion will cause a thought process that will cause smoking.
In the lesion case, I am assuming that the lesion has 100% chance of causing you to make a certain decision.
Sure.
Omega does the same thing; the details of 2 are irrelevant, as long as we know that the lesion will cause a thought process that will cause smoking.
The details of 2 is irrelevant, but the details of how Omage works are relevant. If Omega checks for the lesion, then your choice has no counterfactual causal effect on Omega. If Omega simulates your mind, then your choice does have a counterfactual causal effect.
Lesion -> thought process -> choice.
TDT says choose as if you're determining the outcome of your thought process. If Omega predicts from there, your optimal choice differs from when Omega predicts from Lesion.
= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
= f037147d6e6c911a85753b9abdedda8d){kind=logo}
David Friedman