At this moment, I agree with Psychohistorian that the apparent conundrum is a result of forcing a distinction about causality when there really isn’t one.
On the one hand, we say that the contents of the boxes are not directly, causally related to our choice to one box or two box. (We assert this, I suppose, because of the separation in time between the events, where the boxes are filled before we make our choice.)
On the other hand, we say that Omega can predict with great accuracy what we choose. This implies two things: our decision algorithm for making the choice is pre-written and deterministic, and Omega has access to our decision making algorithm.
Omega bases the contents of the box on the output of our decision making algorithm (that he simulates at time (t-y)) so the contents of the box are directly, causally related to the output of our decision algorithm.
Seems wrong to say that the contents of the box are not causally related to the output of our decision algorithm at time t (i.e., our choice), but are causally related to the output of the decision algorithm at time (t-y) -- even though the decision algorithm is deterministic and hasn’t changed.
In a deterministic system in which information isn’t lost as time progresses, then the time separation between events (positive or negative) makes no difference to the causality … “a causes b” if b depends on a (even if b happens before a). For example, afternoon rain will cause me to bring my umbrella in the morning, in an information-complete system.
Later edit: This represents the location in {comment space}-time where (I think) I’ve understood the solution to Newcomb’s problem, in the context of the substantial clues found here on LW. I had another comment in this thread explaining my solution that I’ve deleted. I don’t want to distract from Anna’s sequence (and I predict the usual philosophical differences) but I’ve kept my deleted comment in case there are more substantial differences.
I would say that the ambiguity/double think about causality is actually the feature of Newcomb’s problem that helps us reduce what causality is.
Of all the comments in this block, byrnema’s seems the most on-track, having the most ingredients of the solution, in my view. A few points:
I prefer to suppose that Omega has a powerful, detailed model of the local world, or whatever parts of the universe are ultimately factors in Joe’s decision. It isn’t just the contents of Joe’s brain. Omega’s track record is strong evidence that his model takes enough into account.
I do not see any backwards-in-time causality in this problem at all. That Joe’s state causes both Omega’s prediction and Joe’s choice is not the same as the choice causing the prediction.
In fact, that’s what seems wrong to me about most of the other comments right here. People keep talking about the choice causing something, but the problem says nothing about this at all. Joe’s choice doesn’t need to cause anything. Instead, Joe’s choice and Omega’s (prediction->money-hiding) have common causes.
The way I see it, the sleight-of-hand in this problem occurs when we ask what Joe “should” do. I think focusing on Joe’s choice leads people to imagine that the choice is free in the sense of being unconnected to Omega’s prediction (since the prediction has already happened). But it is not unconnected, because our choices are not un-caused. Neither are they connected backwards-in-time. Omega’s actions and Joe’s choice are connected because they share common causes.
EDIT: To make this a bit more concrete: Make this a question of what you “should” do if you meet Omega someday. Consider that your decision might be highly influenced by all the musings on the blog, or on Eliezer’s or another poster’s arguments. If these arguments convince you that you should one-box, then they also cause Omega to predict that you’ll one-box. If these arguments fail to convince you, then that circumstance also causes Omega to predict you will two-box.
You’ve got to resist thinking of the machinery of human decision-making as primary or transcendent. See Thou Art Physics.
This represents the location in {comment space}-time where (I think) I’ve understood the solution to Newcomb’s problem, in the context of the substantial clues found here on LW. I had another comment in this thread explaining my solution that I’ve deleted. I don’t want to distract from Anna’s sequence
I’d say go ahead and distract. I’d love to see your solution.
It seems problematic that the boxes are already filled and you are now deciding whether to one box or two box; that your decision can cause the contents of the box to be one way or the other. But it’s not really like that, because your decision has already been determined, even though you don’t know what the decision will be and are even still writing your decision algorithm.
So you are currently in the process of writing your decision algorithm, based on this situation you find yourself in where you need to make a decision. It feels free to you, but of course it isn’t because your “choices” while making the decision algorithm are controlled by other-level functions which are themselves deterministic. These other-level functions “should” compute that their decisions will affect / have affected the outcome and decide to one-box. By “should” I mean that this is best for the decider, but he has no control over how the decision algorithm actually gets written or what the outcome is.
The person that one-boxes will get more money than the person that two-boxes. Since the person has no real choice in the matter, regarding which sort of algorithm they are, you can only say that one is better than the other for getting the most money in this situation, as “should” would imply some kind of free will.
Suppose there is a mutation that causes one species of plants to be hardier than those without the mutation. We would say that one set of plants is better than the other at being hardy. We wouldn’t say that a plant “should” be the hardy variety—they have no choice in the matter.
We are just like plants. Some of us have a better set of states than others for success in whatever. One of these states is an algorithm that computes what to do (makes “choices”) based on predicted consequences of anticipated actions. When we run this algorithm and compute the “chosen action”, it feels on the inside like we are making a choice. It feels like a choice because we input multiple possible actions, and then the algorithm outputs a single action. But really we just happen to have an algorithm that outputs that choice. The algorithm can certainly be modified over time, but the self-modification is deterministic and depends on the environment.
Less Wrong is an environment where we are making the algorithm reflect upon itself. Everyone should consider the possibilities (have an algorithm that one boxes or two boxes?), realize that the one-box algorithm is the one that makes them rich, and update their algorithm accordingly.
Or more precisely: Everyone will consider the possibilities (have an algorithm that one boxes or two boxes?), may realize that having the one-box algorithm is the one that makes them rich, depending on their states, and may update their algorithm accordingly, again depending on their states. People generally have good algorithms, so I predict they will do this unless they have a reason not to. What is that reason?
At this moment, I agree with Psychohistorian that the apparent conundrum is a result of forcing a distinction about causality when there really isn’t one.
On the one hand, we say that the contents of the boxes are not directly, causally related to our choice to one box or two box. (We assert this, I suppose, because of the separation in time between the events, where the boxes are filled before we make our choice.)
On the other hand, we say that Omega can predict with great accuracy what we choose. This implies two things: our decision algorithm for making the choice is pre-written and deterministic, and Omega has access to our decision making algorithm.
Omega bases the contents of the box on the output of our decision making algorithm (that he simulates at time (t-y)) so the contents of the box are directly, causally related to the output of our decision algorithm.
Seems wrong to say that the contents of the box are not causally related to the output of our decision algorithm at time t (i.e., our choice), but are causally related to the output of the decision algorithm at time (t-y) -- even though the decision algorithm is deterministic and hasn’t changed.
In a deterministic system in which information isn’t lost as time progresses, then the time separation between events (positive or negative) makes no difference to the causality … “a causes b” if b depends on a (even if b happens before a). For example, afternoon rain will cause me to bring my umbrella in the morning, in an information-complete system.
Later edit: This represents the location in {comment space}-time where (I think) I’ve understood the solution to Newcomb’s problem, in the context of the substantial clues found here on LW. I had another comment in this thread explaining my solution that I’ve deleted. I don’t want to distract from Anna’s sequence (and I predict the usual philosophical differences) but I’ve kept my deleted comment in case there are more substantial differences.
I would say that the ambiguity/double think about causality is actually the feature of Newcomb’s problem that helps us reduce what causality is.
Of all the comments in this block, byrnema’s seems the most on-track, having the most ingredients of the solution, in my view. A few points:
I prefer to suppose that Omega has a powerful, detailed model of the local world, or whatever parts of the universe are ultimately factors in Joe’s decision. It isn’t just the contents of Joe’s brain. Omega’s track record is strong evidence that his model takes enough into account.
I do not see any backwards-in-time causality in this problem at all. That Joe’s state causes both Omega’s prediction and Joe’s choice is not the same as the choice causing the prediction.
In fact, that’s what seems wrong to me about most of the other comments right here. People keep talking about the choice causing something, but the problem says nothing about this at all. Joe’s choice doesn’t need to cause anything. Instead, Joe’s choice and Omega’s (prediction->money-hiding) have common causes.
The way I see it, the sleight-of-hand in this problem occurs when we ask what Joe “should” do. I think focusing on Joe’s choice leads people to imagine that the choice is free in the sense of being unconnected to Omega’s prediction (since the prediction has already happened). But it is not unconnected, because our choices are not un-caused. Neither are they connected backwards-in-time. Omega’s actions and Joe’s choice are connected because they share common causes.
EDIT: To make this a bit more concrete: Make this a question of what you “should” do if you meet Omega someday. Consider that your decision might be highly influenced by all the musings on the blog, or on Eliezer’s or another poster’s arguments. If these arguments convince you that you should one-box, then they also cause Omega to predict that you’ll one-box. If these arguments fail to convince you, then that circumstance also causes Omega to predict you will two-box.
You’ve got to resist thinking of the machinery of human decision-making as primary or transcendent. See Thou Art Physics.
I’d say go ahead and distract. I’d love to see your solution.
How about if I send you my solution as a message? You can let me know if I’m on the right track or not...
So should you one box or two box?
It seems problematic that the boxes are already filled and you are now deciding whether to one box or two box; that your decision can cause the contents of the box to be one way or the other. But it’s not really like that, because your decision has already been determined, even though you don’t know what the decision will be and are even still writing your decision algorithm.
So you are currently in the process of writing your decision algorithm, based on this situation you find yourself in where you need to make a decision. It feels free to you, but of course it isn’t because your “choices” while making the decision algorithm are controlled by other-level functions which are themselves deterministic. These other-level functions “should” compute that their decisions will affect / have affected the outcome and decide to one-box. By “should” I mean that this is best for the decider, but he has no control over how the decision algorithm actually gets written or what the outcome is.
The person that one-boxes will get more money than the person that two-boxes. Since the person has no real choice in the matter, regarding which sort of algorithm they are, you can only say that one is better than the other for getting the most money in this situation, as “should” would imply some kind of free will.
Suppose there is a mutation that causes one species of plants to be hardier than those without the mutation. We would say that one set of plants is better than the other at being hardy. We wouldn’t say that a plant “should” be the hardy variety—they have no choice in the matter.
We are just like plants. Some of us have a better set of states than others for success in whatever. One of these states is an algorithm that computes what to do (makes “choices”) based on predicted consequences of anticipated actions. When we run this algorithm and compute the “chosen action”, it feels on the inside like we are making a choice. It feels like a choice because we input multiple possible actions, and then the algorithm outputs a single action. But really we just happen to have an algorithm that outputs that choice. The algorithm can certainly be modified over time, but the self-modification is deterministic and depends on the environment.
Less Wrong is an environment where we are making the algorithm reflect upon itself. Everyone should consider the possibilities (have an algorithm that one boxes or two boxes?), realize that the one-box algorithm is the one that makes them rich, and update their algorithm accordingly.
Or more precisely: Everyone will consider the possibilities (have an algorithm that one boxes or two boxes?), may realize that having the one-box algorithm is the one that makes them rich, depending on their states, and may update their algorithm accordingly, again depending on their states. People generally have good algorithms, so I predict they will do this unless they have a reason not to. What is that reason?