Re: “physics-based priors,” I don’t think I have a full sense of what you have in mind, but at a high level, I don’t yet see how physics comes into the debate. That is, AFAICT everyone agrees about the relevant physics — and in particular, that you can’t causally influence the past, “change” the past, and so on. The question as I see it (and perhaps I should’ve emphasized this more in the post, and/or put things less provocatively) is more conceptual/normative: whether when making decisions we should think of the past the way CDT does — e.g., as a set of variables whose probabilities our decision-making can’t alter — or in the way that e.g. EDT does — e.g., as a set of variables whose probabilities our decision-making can alter (and thus, a set of variables that EDT-ish decision-making implicitly tries to “control” in a non-causal sense). Non-causal decision theories are weird; but they aren’t actually “I don’t believe in normal physics” weird. They’re more “I believe in managing the news about the already-fixed past” weird.
Re: CDT’s domain of applicability, it sounds like your view is something like: “CDT generally works, but it fails in the type of cases that Joe treats as counter-examples to CDT.” I agree with this, and I think most people who reject CDT would agree, too (after all, most decision theories agree on what to do in most everyday cases; the traditional questions have been about what direction to go when their verdicts come apart). I’m inclined to think of this as CDT being wrong, because I’m inclined to think of decision theory as searching for the theory that will get the full range of cases right — but I’m not sure that much hinges on this. That said, I do think that even acknowledging that CDT fails sometimes involves rejecting some principles/arguments one might’ve thought would hold good in general (e.g. “c’mon, man, it’s no use trying to control the past,”the “what would your friend who can see what’s in the boxes say is better” argument, and so on) and thereby saying some striking and weird stuff (e.g. “Ok, it makes sense to try to control the past sometimes, just not that often”).
Re: 1-4, I agree that whether or not CDT leads you astray in a given case is an empirical question. I don’t have strong views about what range of actual cases are like this — though I’m sympathetic to your view re: 1, and as I mention in the post, I generally think we should just err on the side of not doing stuff that looks silly by normal lights. I also don’t have strong views about the relevance of non-causal decision-theory research for AGI safety (this project mostly emerged from personal interest).
By “physics-based” I’m lumping together physics and history a bit, but it’s hard to disentangle them especially when people start talking about multiverses. I generally mean “the combined information of the laws of physics and our knowledge of the past”. The reason I do want to cite physics too, even for the past case of (1), is that if you somehow disagreed about decision theorists in WW1 I’d go to the next part of the argument, which is that under the technology of WW1 we can’t do the necessary predictive control (they couldn’t build deterministic twins back then).
However, it seems like we’re mostly in agreement, and you could consider editing the post to make that more clear. The opening line of your post is “I think that you can “control” events you have no causal interaction with, including events in the past.” Now the claim is “everyone agrees about the relevant physics — and in particular, that you can’t causally influence the past”. These two sentences seem inconsistent, and especially since your piece is long and quite technical opening with a wrong summary may confuse people.
I realize you can get out of the inconsistency by leaning on the quotes, but it still seems misleading.
Ah, I see: you’re going to lean on the difference between “cause” and “control”. So to be clear: I am claiming that, as an empirical matter, we also can’t control the past, or even “control” the past.
To expand, I’m not using physics priors to argue that physics is causal, so we can’t control the past. I’m using physics and history priors to argue that we exist in the non-prediction case relative to the past, so CDT applies.
Cool, this gives me a clearer picture of where you’re coming from. I had meant the central question of the post to be whether it ever makes sense to do the EDT-ish try-to-control-the-past thing, even in pretty unrealistic cases—partly because I think answering “yes” to this is weird and disorienting in itself, even if it doesn’t end up making much of a practical difference day-to-day; and partly because a central objection to EDT is that the past, being already fixed, is never controllable in any practically-relevant sense, even in e.g. Newcomb’s cases. It sounds like your main claim is that in our actual everyday circumstances, with respect to things like the WWI case, EDTish and CDT recommendations don’t come apart—a topic I don’t spend much time on or have especially strong views about.
“you’re going to lean on the difference between ‘cause’ and ‘control’”—indeed, and I had meant the “no causal interaction with” part of opening sentence to indicate this. It does seem like various readers object to/were confused by the use of the term “control” here, and I think there’s room for more emphasis early on as to what specifically I have in mind; but at a high-level, I’m inclined to keep the term “control,” rather than trying to rephrase things solely in terms of e.g. correlations, because I think it makes sense to think of yourself as, for practical purposes, “controlling” what your copy writes on his whiteboard, what Omega puts in the boxes, etc; that more broadly, EDT-ish decision-making is in fact weird in the way that trying to control the past is weird, and that this makes it all the more striking and worth highlighting that EDT-ish decision-making seems, sometimes, like the right way to go.
Thanks for these comments.
Re: “physics-based priors,” I don’t think I have a full sense of what you have in mind, but at a high level, I don’t yet see how physics comes into the debate. That is, AFAICT everyone agrees about the relevant physics — and in particular, that you can’t causally influence the past, “change” the past, and so on. The question as I see it (and perhaps I should’ve emphasized this more in the post, and/or put things less provocatively) is more conceptual/normative: whether when making decisions we should think of the past the way CDT does — e.g., as a set of variables whose probabilities our decision-making can’t alter — or in the way that e.g. EDT does — e.g., as a set of variables whose probabilities our decision-making can alter (and thus, a set of variables that EDT-ish decision-making implicitly tries to “control” in a non-causal sense). Non-causal decision theories are weird; but they aren’t actually “I don’t believe in normal physics” weird. They’re more “I believe in managing the news about the already-fixed past” weird.
Re: CDT’s domain of applicability, it sounds like your view is something like: “CDT generally works, but it fails in the type of cases that Joe treats as counter-examples to CDT.” I agree with this, and I think most people who reject CDT would agree, too (after all, most decision theories agree on what to do in most everyday cases; the traditional questions have been about what direction to go when their verdicts come apart). I’m inclined to think of this as CDT being wrong, because I’m inclined to think of decision theory as searching for the theory that will get the full range of cases right — but I’m not sure that much hinges on this. That said, I do think that even acknowledging that CDT fails sometimes involves rejecting some principles/arguments one might’ve thought would hold good in general (e.g. “c’mon, man, it’s no use trying to control the past,”the “what would your friend who can see what’s in the boxes say is better” argument, and so on) and thereby saying some striking and weird stuff (e.g. “Ok, it makes sense to try to control the past sometimes, just not that often”).
Re: 1-4, I agree that whether or not CDT leads you astray in a given case is an empirical question. I don’t have strong views about what range of actual cases are like this — though I’m sympathetic to your view re: 1, and as I mention in the post, I generally think we should just err on the side of not doing stuff that looks silly by normal lights. I also don’t have strong views about the relevance of non-causal decision-theory research for AGI safety (this project mostly emerged from personal interest).
By “physics-based” I’m lumping together physics and history a bit, but it’s hard to disentangle them especially when people start talking about multiverses. I generally mean “the combined information of the laws of physics and our knowledge of the past”. The reason I do want to cite physics too, even for the past case of (1), is that if you somehow disagreed about decision theorists in WW1 I’d go to the next part of the argument, which is that under the technology of WW1 we can’t do the necessary predictive control (they couldn’t build deterministic twins back then).
However, it seems like we’re mostly in agreement, and you could consider editing the post to make that more clear. The opening line of your post is “I think that you can “control” events you have no causal interaction with, including events in the past.” Now the claim is “everyone agrees about the relevant physics — and in particular, that you can’t causally influence the past”. These two sentences seem inconsistent, and especially since your piece is long and quite technical opening with a wrong summary may confuse people.
I realize you can get out of the inconsistency by leaning on the quotes, but it still seems misleading.
Ah, I see: you’re going to lean on the difference between “cause” and “control”. So to be clear: I am claiming that, as an empirical matter, we also can’t control the past, or even “control” the past.
To expand, I’m not using physics priors to argue that physics is causal, so we can’t control the past. I’m using physics and history priors to argue that we exist in the non-prediction case relative to the past, so CDT applies.
Cool, this gives me a clearer picture of where you’re coming from. I had meant the central question of the post to be whether it ever makes sense to do the EDT-ish try-to-control-the-past thing, even in pretty unrealistic cases—partly because I think answering “yes” to this is weird and disorienting in itself, even if it doesn’t end up making much of a practical difference day-to-day; and partly because a central objection to EDT is that the past, being already fixed, is never controllable in any practically-relevant sense, even in e.g. Newcomb’s cases. It sounds like your main claim is that in our actual everyday circumstances, with respect to things like the WWI case, EDTish and CDT recommendations don’t come apart—a topic I don’t spend much time on or have especially strong views about.
“you’re going to lean on the difference between ‘cause’ and ‘control’”—indeed, and I had meant the “no causal interaction with” part of opening sentence to indicate this. It does seem like various readers object to/were confused by the use of the term “control” here, and I think there’s room for more emphasis early on as to what specifically I have in mind; but at a high-level, I’m inclined to keep the term “control,” rather than trying to rephrase things solely in terms of e.g. correlations, because I think it makes sense to think of yourself as, for practical purposes, “controlling” what your copy writes on his whiteboard, what Omega puts in the boxes, etc; that more broadly, EDT-ish decision-making is in fact weird in the way that trying to control the past is weird, and that this makes it all the more striking and worth highlighting that EDT-ish decision-making seems, sometimes, like the right way to go.