The disagreement is about what to do. I have uniformly meant "ought" in the action sense, not the dispositional sense. (FYI: this is always the sense in which philosophers (incl. Richard) mean "ought", unless otherwise specified.)
That sense is entirely uninteresting, as I explained in my first comment in this thread. It's the sense in which one "ought" to two-box after having been predicted by Omega to one-box -- a stipulated impossibility.
Philosophers who, after having considered the distinction, remain concerned with the "action" sense, would tend to be -- shall we say -- vehemently suspected of non-reductionist thinking; of forgetting that actions are completely determined by dispositions (i.e. the algorithms running in the mind of the agent).
Having said that, if one does use "ought" in the action sense, then there should be no difficulty in saying that one "ought" to two-box in the situation where Omega has predicted you will one-box. That's just a restatement of the assumption that the outcome of (one-box predicted, two-box) is higher in the preference ordering than that of (one-box predicted, one-box).
Normally, the two meanings of "ought" coincide, because outcomes normally depend on actions that happen to be determined by dispositions, not directly on dispositions themselves. Hence it's easy to be deceived into thinking that the action sense is the appropriate sense of "ought". But this breaks down in situations of the Newcomb type. There, the dispositional sense is clearly the right one, because that's the sense in which you ought to one-box; since the dispositional sense also gives the same answers as the action sense for "normal" situations, we may as well say that the dispositional sense is what we mean by "ought" in general.
So, you're really interested in this question: what is the best decision algorithm? And then you're interested, in a subsidiary way, in what you ought to do. You think the "action" sense is silly, since you can't run one algorithm and make some other choice.
Your answer to my objection involving the parody argument is that you ought to do something else (not go with loss aversion) because there is some better decision algorithm (that you could, in some sense of "could", use?) that tells you to do something else.
What do you do with case...
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.