In particular, I’d argue that the paradoxical aspects of Newcomb’s problem result from exactly this kind of confusion between the usual agent idealization and the fact that actual actors (human beings) are physical beings subject to the laws of physics. The apparent paradoxical aspects results because we are used to idealizing individual behavior in terms of agents where that formalism requires we specify the situation in terms of a tree of possibilities with each path corresponding to an outcome and with the payoff computed by looking at the path specified by all agent’s choices (e.g. there is a node where the demon player chooses what money to put in the boxes and then there is a node where the human player, without knowledge of demon player’s choices, decides to take both boxes or neither). The agent formalization (where 1 or 2 boxing is modeled as a subsequent choice) simply doesn’t allow the content of the boxes to depend on whether or not the human agent chooses 1 or 2 boxes.
Of course, since actual people aren’t ideal agents one can argue that something like the newcomb demon is physically possible but that’s just a way of specifying that we are in a situation where the agent idealization breaks down.
This means there is simply no fact of the matter about how a rational agent (or whatever) should behave in newcomb type situations because the (usual) rational agent idealization is incompatible with the newcomb situation (ok, more technically you can model it that way but the choice of how to model it just unsatisfactorily builds in the answer by specifying how the payoff depends on 1 vs two boxing).
To sum up what the answer to the newcomb problem is depends heavily on how you preciscify the question. Are you asking whether humans who are disposed to decide in way A end up better of than humans disposed to behave in way B? In that case it’s easy. But things like CDT, TDT etc.. don’t claim to be producing facts of that kind but rather saying something about ideal rational agents of some kind which then just boringly depends on a ambiguities in what we mean by that.ideal rational agents.
“This means there is simply no fact of the matter about how a rational agent (or whatever) should behave in newcomb type situations”—this takes this critique too far. Just because the usual agent idealisation breaks, it doesn’t follow that we can’t create a new idealisation that covers these cases.
Obviously you can and if you define that NEW idealization an X-agent (or more likely redefine the word rationality in that situation) and then there may be a fact of the matter about how an X-agent will behave in such situations. What we can’t do is assume that there is a fact of the matter about what a rational agent will do that outstrips the definition.
As such it doesn’t make sense to say CDT is right or TDT or whatever before introducing a specific idealization relative to which we can prove they give the correct answer. But that idealization has to come first and has to convince the reader that it is a good idealization.
But the rhetoric around these decision theories misleadingly tries to convince us that there is some kind of pre-existing notion of rational agent and they have discovered that XDT gives the correct answer for that notion. That’s what makes people view these claims as interesting. If the claim was nothing more than ’here is one way you can make decisions corresponding to the following assumptions” it would be much more obscure and less interesting.
There are pre-formal facts about what words should mean, or what meanings to place in the context where these words may be used. You test a possible definition against the word’s role in the story, and see if it’s apt. This makes use of facts outside any given definition, just as with the real world.
And here, it’s not even clear what the original definitions of agents should be capable of, if you step outside particular decision theories and look at the data they could have available to them. Open source game theory doesn’t require anything fundamentally new that a straightforward idealization of an agent won’t automatically represent. It’s just that the classical decision theories will discard that data in their abstraction of agents. In Newcomb’s problem, it’s essentially discarding part of the problem statement, which is a strange thing to expect of a good definition of an agent that needs to work on the problem.
Except if you actually go try and do the work people’s pre-theoretic understanding of rationality doesn’t correspond to a single precise concept.
Once you step into Newcomb type problems it’s no longer clear how decision theory is supposed to correspond to the world. You might be tempted to say that decision theory tells you the best way to act...but it no longer does that since it’s not that the two-boxer should have picked one box. The two-boxer was incapable of so picking and what EDT is telling you is something more like: you should have been the sort of being who would have been a one boxer not that *you* should have been a one boxer.
Different people will disagree over whether their pre-theoretic notion of rationality is one in which it is correct to say that it is rational to be a one/two boxer. Classic example of working with a imprecisely defined concept.
In particular, I’d argue that the paradoxical aspects of Newcomb’s problem result from exactly this kind of confusion between the usual agent idealization and the fact that actual actors (human beings) are physical beings subject to the laws of physics. The apparent paradoxical aspects results because we are used to idealizing individual behavior in terms of agents where that formalism requires we specify the situation in terms of a tree of possibilities with each path corresponding to an outcome and with the payoff computed by looking at the path specified by all agent’s choices (e.g. there is a node where the demon player chooses what money to put in the boxes and then there is a node where the human player, without knowledge of demon player’s choices, decides to take both boxes or neither). The agent formalization (where 1 or 2 boxing is modeled as a subsequent choice) simply doesn’t allow the content of the boxes to depend on whether or not the human agent chooses 1 or 2 boxes.
Of course, since actual people aren’t ideal agents one can argue that something like the newcomb demon is physically possible but that’s just a way of specifying that we are in a situation where the agent idealization breaks down.
This means there is simply no fact of the matter about how a rational agent (or whatever) should behave in newcomb type situations because the (usual) rational agent idealization is incompatible with the newcomb situation (ok, more technically you can model it that way but the choice of how to model it just unsatisfactorily builds in the answer by specifying how the payoff depends on 1 vs two boxing).
To sum up what the answer to the newcomb problem is depends heavily on how you preciscify the question. Are you asking whether humans who are disposed to decide in way A end up better of than humans disposed to behave in way B? In that case it’s easy. But things like CDT, TDT etc.. don’t claim to be producing facts of that kind but rather saying something about ideal rational agents of some kind which then just boringly depends on a ambiguities in what we mean by that.ideal rational agents.
“This means there is simply no fact of the matter about how a rational agent (or whatever) should behave in newcomb type situations”—this takes this critique too far. Just because the usual agent idealisation breaks, it doesn’t follow that we can’t create a new idealisation that covers these cases.
Obviously you can and if you define that NEW idealization an X-agent (or more likely redefine the word rationality in that situation) and then there may be a fact of the matter about how an X-agent will behave in such situations. What we can’t do is assume that there is a fact of the matter about what a rational agent will do that outstrips the definition.
As such it doesn’t make sense to say CDT is right or TDT or whatever before introducing a specific idealization relative to which we can prove they give the correct answer. But that idealization has to come first and has to convince the reader that it is a good idealization.
But the rhetoric around these decision theories misleadingly tries to convince us that there is some kind of pre-existing notion of rational agent and they have discovered that XDT gives the correct answer for that notion. That’s what makes people view these claims as interesting. If the claim was nothing more than ’here is one way you can make decisions corresponding to the following assumptions” it would be much more obscure and less interesting.
There are pre-formal facts about what words should mean, or what meanings to place in the context where these words may be used. You test a possible definition against the word’s role in the story, and see if it’s apt. This makes use of facts outside any given definition, just as with the real world.
And here, it’s not even clear what the original definitions of agents should be capable of, if you step outside particular decision theories and look at the data they could have available to them. Open source game theory doesn’t require anything fundamentally new that a straightforward idealization of an agent won’t automatically represent. It’s just that the classical decision theories will discard that data in their abstraction of agents. In Newcomb’s problem, it’s essentially discarding part of the problem statement, which is a strange thing to expect of a good definition of an agent that needs to work on the problem.
Except if you actually go try and do the work people’s pre-theoretic understanding of rationality doesn’t correspond to a single precise concept.
Once you step into Newcomb type problems it’s no longer clear how decision theory is supposed to correspond to the world. You might be tempted to say that decision theory tells you the best way to act...but it no longer does that since it’s not that the two-boxer should have picked one box. The two-boxer was incapable of so picking and what EDT is telling you is something more like: you should have been the sort of being who would have been a one boxer not that *you* should have been a one boxer.
Different people will disagree over whether their pre-theoretic notion of rationality is one in which it is correct to say that it is rational to be a one/two boxer. Classic example of working with a imprecisely defined concept.