Rationality and winning may not be the same thing. But I do think they’re linked. If we’re asked to judge whether the principle of strong dominance is rational, we say yes because it always leads to the best outcome (leads to “winning”). If we were asked to choose from a 10% chance of winning $100 or a 20% chance, we would say it was rational to choose the 20% chance, once again because there’s a higher chance of winning.
In fact, it seems to me that people do judge whether a decision is rational based on whether it leads to "winning" but they just get confused by multiple possible meanings of winning in the case of Newcomb's Problem which I think comes from confusing two possible questions about the rationality of a decision in the problem (discussed later).
Regardless, even if that's not true, it seems that rationality and winning are at least related.
Now I believe that, in just the same way, the rationality of a decision theory or procedure can be judged based on the same basis. So it may be rational to follow TDT instead of CDT (as an example, I’m not getting into the conversation of which is better here) because it may lead to a greater chance of winning. The justification here is just the same as it is in the strong dominance and lottery example in the first paragraph.
Which means there are two questions: 1.) What is the rational decision to make in the circumstance? The answer here may well be the strongly dominant decision (two boxing) 2.) What is the rational decision theory to follow? The answer here might be (for example) TDT and hence the decision that flows from this is one boxing.
But that means the question of whether one boxing or two boxing is the rational decision in the case of Newcomb’s Problem can mean one of two things: 1.) Is it a rational decision? 2.) Did it follow from a rational decision theory?
Previously, I provided more weight to the second of these and said that as it followed from a rational decision theory, that was what mattered. I still feel like that’s right (like the meta level should override the normal) but I need to think on it more to figure out if I have a real justification for it. So let’s say both levels are equally important. So, given that, I would agree that two boxing is the rational decision.
However, when it comes to creating better or worse decision theories, I think the relevant question is whether the decision theory is rational, not whether the decisions it entails are. After all, we are judging between decision theories and hence the decision theory perspective seems more relevant.
But let’s say you totally disagree with my definition of rationality (my first question would be, how do you define rationality and how does this lead to strong dominance being seen as rational rather than just seen as a winning technique? Which is to say, I wonder whether your question can be applied to many things we already see as rational as easily as it can be applied to these contested issues – maybe I’m wrong there though). But regardless, I think I’m getting too caught up in this question of rationality.
Rationality is an important issue but I think a decision theory should be about making “winning” decision and if rationality and winning aren’t even linked in your definitions, then I would say that decision theories are meant to be about how to make decisions. I think their success should be measured based on whether they lead to the best outcomes not based on an arbitrary (or none arbitrary, for that matter), definition of rationality.
So let’s say two boxing is the rational decision in Newcomb’s Problem. I’m not sure I care. I’m more interested in whether we can come up with a decision theory that comes up with a better outcome and I personally will judge such a decision theory higher than one that meets so-and-so definition of rationality but doesn’t lead to such results.
decision theory should be about making “winning” decision
But remember, in Newcomb the one-boxer wins in virtue of her disposition, not in virtue of her decision per se.
On your broader point, I agree that we need to distinguish the two questions you note, though I find it a little obscure to talk of a "rational decision theory" (as by this I had previously taken you to mean the theory which correctly specifies rational decisions, when you really mean something more like what I'm calling desirable dispositions). I agree with you that one-boxing...
A common background assumption on LW seems to be that it's rational to act in accordance with the dispositions one would wish to have. (Rationalists must WIN, and all that.)
E.g., Eliezer:
And more recently, from AdamBell:
Within academic philosophy, this is the position advocated by David Gauthier. Derek Parfit has constructed some compelling counterarguments against Gauthier, so I thought I'd share them here to see what the rest of you think.
First, let's note that there definitely are possible cases where it would be "beneficial to be irrational". For example, suppose an evil demon ('Omega') will scan your brain, assess your rational capacities, and torture you iff you surpass some minimal baseline of rationality. In that case, it would very much be in your interests to fall below the baseline! Or suppose you're rewarded every time you honestly believe the conclusion of some fallacious reasoning. We can easily multiply cases here. What's important for now is just to acknowledge this phenomenon of 'beneficial irrationality' as a genuine possibility.
This possibility poses a problem for the Eliezer-Gauthier methodology. (Quoting Eliezer again:)
The problem, obviously, is that it's possible for irrational agents to receive externally-generated rewards for their dispositions, without this necessarily making their downstream actions any more 'reasonable'. (At this point, you should notice the conflation of 'disposition' and 'choice' in the first quote from Eliezer. Rachel does not envy Irene her choice at all. What she wishes is to have the one-boxer's dispositions, so that the predictor puts a million in the first box, and then to confound all expectations by unpredictably choosing both boxes and reaping the most riches possible.)
To illustrate, consider (a variation on) Parfit's story of the threat-fulfiller and threat-ignorer. Tom has a transparent disposition to fulfill his threats, no matter the cost to himself. So he straps on a bomb, walks up to his neighbour Joe, and threatens to blow them both up unless Joe shines his shoes. Seeing that Tom means business, Joe sensibly gets to work. Not wanting to repeat the experience, Joe later goes and pops a pill to acquire a transparent disposition to ignore threats, no matter the cost to himself. The next day, Tom sees that Joe is now a threat-ignorer, and so leaves him alone.
So far, so good. It seems this threat-ignoring disposition was a great one for Joe to acquire. Until one day... Tom slips up. Due to an unexpected mental glitch, he threatens Joe again. Joe follows his disposition and ignores the threat. BOOM.
Here Joe's final decision seems as disastrously foolish as Tom's slip up. It was good to have the disposition to ignore threats, but that doesn't necessarily make it good idea to act on it. We need to distinguish the desirability of a disposition to X from the rationality of choosing to do X.