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Kingreaper comments on The Smoking Lesion: A problem for evidential decision theory - Less Wrong
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Nope. In the Newcombian situation the lines of causality are different.
What's in the box is explicitly caused by what you will choose, whereas in the smoking lesion example they simply share a cause.
Different lines of causality, different scenario.
No. What is in the box is not caused by what you will choose. It is caused by Omega after analyzing your original disposition, before the game begins. After you start the game, your choice and the million share a cause, namely your original disposition. So the cases are the same-- same lines of causality, same scenario.
You can no more change your original disposition (which causes the million), than you can change the lesion that causes cancer.
You can control your original disposition in exactly the same way you usually control your decisions. Even normally when you consider a decision the outcome is already settled and the measure of all Everett branches involved already determined. Just because you consider the counterfactual of local miracles that result in a different decision when evaluating your preferences doesn't mean any such local miracles actually happen. Your original disposition is caused by your preferences between the two "possible" actions, just like with any other decision. The lesion example is different because your preferences are at no point involved in the causal history of the cancer.
Even going on that basis, which I disagree with (I disagree with the "lack of simulation" hypothesis; see the other thread of comments in a second)
Right now, I could precommit myself to winning in all newcomb-like problems I encounter in future, and thus, right now, I can change my disposition.
I can't precommit to not finding something irresistable due to brain damage/lesions/whatever.
That's a pretty significant difference.
You can precommit to not smoking in the same way you can precommit to taking only one box. If you might later find smoking irresistable, you might later find taking both boxes irresistable.
Precommitting changes my disposition, making me not find two-boxing irresistable.
Precommitting CAN'T change whether I get the lesion or not.
In Newcombs scenario, precommitting changes the outcome. In the smoking lesion, it doesn't.
Precommitting not to smoke also changes my disposition regarding smoking. I still might find it irresistable later. Likewise if I precommit to one box. That says nothing about how I will feel about it later, when the situation happens.
In fact, even in real life, I suspect many one-boxers would two box in the end when they are standing there and thinking, "Either the million is there or it isn't, and there's nothing I can do about it." In other words, they might very well find two-boxing irresistable, even if they had precommitted.
If they give in, they have not successfully precommitted. Now, you could argue that successfully precommitting is impossible. But in the Newcombian problem, it doesn't seem to be.
In the Lesion problem, the problem involves what essentially amounts to brain-damage, which gives a clear reason why precommitment is impossible.
This misses the point. If precommitting changes your disposition, and your disposition decides the outcome, precommitting is worthwhile.
If precommitting changes your disposition, and a lesion decides the outcome, precommitting is irrelevant.
Actually, talking about precommitting is any case a side issue, because it happens before the start of the game. We can just assume you've never thought it before Omega comes up to you, says that it has predicted your decision, and tells you the rules. Now what do you do?
In this case the situation is clearly the same as the lesion, and the lines of causality are the same: both your present disposition, and the million in the box, have a common cause, namely your previous disposition, but you can do nothing about it.
If you should one-box here, then you should not smoke in the lesion case.
My intuition says the opposite: I think many people who claimed they would two-box would one-box in the event. $1000 is so small compared to $1000000, after all; why take the chance that Omega will be wrong?
I find that the term "cause" or "causality" can be very misleading in this situation.
As a matter of terminology, I actually agree with you: in lay speech, I see nothing wrong with saying that "One-boxing causes the sealed box to be filled", because this is exactly how we perceive causality in the world.
However, when speaking of these problems, theorists nail down their terminology as best they can. And in such problems, standard usage is such that the concept of causality only applies to cases where an event changes things solely in the future[1], not merely where it reveals you to be in a situation in which a past event has happened.
When speaking of decision-theoretic problems, it is important to stick to this definition of causality, counter-intuitive though it may be.
Another example of the distinction is in Drescher's Good and Real. Consider this: if you raise your hand (in a deterministic universe), you are setting the universe's state 1 billion years ago to be such that a chain of events will unfold in a way that, 1 billion years later, you will raise your hand. In a (lay) sense, raising your hand "caused" that state.
However, because that state is in the past, it violates decision-theoretic usage to say that you caused that state; instead, you should simply say that either:
a) there is an acausal relationship between your choice to raise your hand and that state of the universe, or
b) by choosing to raise your hand, you have learned about a past state of universe. (Just as deciding whether to exit in the Absent-Minded Driver problem tells you something about which exit you are at.)
[1] or, in timeless formalisms, where the cause screens off that which it causes.
I think you've misunderstood me. "What you will choose" is a fact that exists before omega fills the boxes.
This fact determines how the boxes are filled.
"What you will choose" (some people seem to refer to this, or something similar, as your "disposition", but I find my terminology more immediately apparent) causes the future event "how the boxes are filled"
Oh, sorry. Some of this stuff is just tough to parse, but your points are correct.
I'll leave up the previous post because it's an important thing to keep in mind.
Indeed. I'll try to be clearer in future.
That isn't relevant. For all you know, Omega also created the universe, and so set it in the situation that disposed you to choose the way you did.
When the game actually begins, you cannot change your disposition, and you cannot change the million dollars.
Someone should wrap it up with a problem where what you choose is determined by what's in the box. Any ideas, anyone?
Actually, this is excellent. We could rewrite Newcomb's problem like this:
Omega places in the box together with the million or non-million, a device that influences your brain, programming the device so that you are caused to take both if it does not place the million, and programming the device so that you are caused to one-box if it places the million. In other words, Omega decides in advance whether you are going to get the million or not, then sets up the situation so you will make the choice that gets you what it wanted you to get.
However, the influence on your brain is quite subtle; to you, it still feels like you are deciding in the normal way, using some decision theory or other.
Now, do you one-box or two-box? This is certainly exactly the same as the smoking lesion. Nor can you answer "I don't have to decide because my actions are determined" because your actions might well be determined in real life anyway, and you still have to decide.
If you one-box here, you should not smoke in the lesion problem. If you don't one-box here... well, too bad for you.
The obvious answer is ‘whatever Omega decided’. But I hope that I one-box.
You might as well say in general that you do "whatever the laws of physics determine."
But you still have to decide, anyway. Hoping doesn't help.
I flip a coin; if it's heads, I give you a million dollars, else I give you a thousand dollars. How much money should you get from me? (And is this problem any different from the last one?)
At some point, these questions no longer help us make rational decisions. Even an AI with complete access to its source code can't do anything to prepare itself for these situations.
No, you don't, you don't get to decide. The decision has been made.
You're ignoring the fact that, normally, the thoughts going on in your brain are PART of how the decision is determined by the laws of physics. In your scenario, they're irrelevant. Whatever you think, your action is determined by the machine.
EDIT: http://lesswrong.com/lw/2mc/the_smoking_lesion_a_problem_for_evidential/2hx7?c=1 You've claimed that you would one-box in this scenario. You've claimed therefore, that you would one-box if programmed to two-box.
Ie. you've claimed you're capable of logically impossible acts. Either that, or you don't understand your own scenario.
The machine works only by getting you to think certain things, and these things cause your decision. So you decide in the same way you normally do.
I did not say I would one box if I were programmed to two box; I said I would one-box.
And if you were programmed to two-box, and unaware of that fact?
Your response is like responding to "what would you do if there was a 50% chance of you dying tomorrow?" with: "I'd survive"
It completely ignores the point of the situation, and assumes godlike agency.
I do whatever I'm being influenced into doing.
This is a fact.
You can argue all you like about what I should do, but what I will do is already decided, and isn't influenced by my thoughts, my rationality, or anything else.
All the information needed to determine what I will do is in the lesion/machine.
Applying rationality to a scenario where the agent is by definition incapable of rationality is just plain silly.
Do you think that in real life you are exempt from the laws of physics?
If not, does that mean that "what you will do is already decided"? That you don't have to make a decision? That you are "incapable of rationality"?
In the real world the information that determines my action is contained within me. In order to determine the action, you would have to run "me" (or at least some reasonable part thereof)
In your version of newcombs the information that determines my action is contained within the machine.
Can you see why I consider that a significant difference?
No. The machine determines your action only by determining what is in you, which determines your action in the normal way.
So you still have to decide what to do.
Do you see how this scenario rules out the possibility of me deciding rationally?
EDIT: In fact, let me explain now, before you answer, give me a sec and I'll re-edit
EDIT2: If the rational decision is to two-box, and Omega has set me to one-box, then I must not be deciding rationally. Correct?
If the rational decision is to one-box, and Omega has set me to two-box, then I must not be deciding rationally. Correct?
Now, assuming I will not decide rationally, as I know I will not, I need waste no time thinking. I'll do whichever I feel like.
You can substitute "the laws of physics" for "Omega" in your argument, and if it proves you will not decide rationally in the Omega situation, then it proves you will not decide --anything-- rationally in real life.
Presumably (or at least hopefully) if you are a rational agent with a certain DT, then a long and accurate description of the ways that "the laws of physics" affect your decision-making process break down into
It's not clear how a reduction like this could work in your example.
No, it proves I will not decide everything rationally if I don't decide everything rationally. Which is pretty tautologous.
The Omega example requires that I will not decide everything rationally.
The real world permits the possibility of a rational agent. Thus it makes sense to question what a rational agent would do. Your scenario doesn't permit a rational agent, thus it makes no sense to ask what a rational agent would do.
You're missing the point Unknowns. In your scenario, my decision doesn't depend on how I decide. It just depends on the setting of the box. So I might as well just decide arbitrarily, and save effort.
What would you do in your own scenario?
You left out some steps in your argument. It appears you were going for a disjunction elimination, but if so I'm not convinced of one premise. Let me lay out more explicitly what I think your argument is supposed to be, then I'll show where I think it's gone wrong.
A = "The rational decision is to two-box" B = "Omega has set me to one-box" C = "The rational decision is to one-box" D = "Omega has set me to two-box" E = "I must not be deciding rationally"
I'll grant #1 and #2. This is a valid argument, but the dubious proposition is #3. It is entirely possible that (A∧D) or that (C∧B). And in those cases, E is not guaranteed.
In short, you might decide rationally in cases where you're set to one-box and it's rational to one-box.
Proposition 3 is only required to be possible, not to be true, and is supported by the existence of both paths of the scenario: the scenario requires that both A and B are possible.
It is possible that I will make the rational decision in one path of the scenario. But the scenario contains both paths. In one of the two paths I must be deciding irrationally.
Given as it was stated that I will use my normal thought-processes in both paths, my normal thought-processes must, in order for this scenario to be possible, be irrational.
Every event has multiple causes, and what causes you point out is not such important as you seem to think. In Newcomb, Omega's decision and your one-or-two-boxing are both ultimately consequences of the state of the world before the scenario has started.
The only difference between Newcomb and the lesion is that in case of 100% effective lesion, there will be no correlation between having read about EDT and smoking. And in a world where there was such a correlation, one should start believing in fate.