Christensen on Probabilism

I was reading David Christensen’s 2001 paper “Preference-Based Arguments for Probabilism” (Philosophy of Science) and I was struck by what seemed to be a gap in the argument.

Christensen is interested in arguments for probabilism based around representation theorems. The argument Patrick Maher gives in _Betting on Theories_ is as good as any, so we’ll work with it. Maher notes that anyone who has preferences that satisfy certain constraints can be represented by a probability function and a utility function such that they prefer A to B if the expected utility of A (acc to those functions) is higher than B. The intended conclusion is that our degrees of belief _should_ form probability functions.

Now as Christensen notes, there’s a gap between premise and conclusion here. He takes Maher to be filling it by _analysing_ degrees of belief as dispositions to bet, and hence making an analytic/metaphysical connection between the preferences (which by hypothesis satisfy the axioms) and the degrees of belief that we can uniquely represent the agent as having. (There’s a complication to do with the fact that on Maher’s theory the probability function is not defined uniquely. We’ll bracket that issue here.) Hence the requirement to have preferences that satisfy the axioms just is the requirement to have degrees of belief that form probability functions.

If that’s what Maher is doing (and I don’t want to get into exegetical debates about this, so this isn’t directed at Maher as much as at Maher under a (mis)interpretation) then it seems bad. Functionalism is a good theory of mental content, but not so simple a functionalism as displayed here. Christensen has made this point in a few places, and it’s a very good point, one that should receive more attention than it does I believe.

Christensen thinks we can bridge the gap normatively. He endorses the following principle

bq. *Informed Preference*: An _ideally rational_ agent prefers the option of getting a desirable prize if _B_ obtains to the option of getting the same prize if _A_ obtains, just in csae _B_ is more probable for that agent than _A_.

He doesn’t say much more, but I think from the context that’s meant to fill in the gap between the representation theorem and probabilism. But it doesn’t, not by a long way, as the following example shows.

Jack’s preferences are only defined over bets to do with the truth or falsity of p, and Boolean constructions from p. He is logically omniscient, so he knows which things are equivalent to p, which to ~p, which to p v ~p and which to p & ~p. His betting dispostions are entirely as if he was maximising expected utility according to a probability function that assigned 1/2 to p (and its equivalents) and 1/2 to ~p (and its equivalents). So he satisfies all of Maher’s axioms. But in fact his degree of belief in p is 1/3, and his degree of belief in ~p is 1/3. (Christensen is committed to this being _possible_, so I’m not begging any questions yet by raising it.)

Note that Jack satisfies *Informed Preference*. But he is irrational by the lights of Probabilism. So an argument for Probabilism of the kind Christensen wants will have to have a much stronger principle than that. One such principle would be a *Maximise Expected Utility* principle, but Christensen rightly notes that would have little force.

I think we can rescue Christensen’s argument by an additional premise.

For any rational agent there is some subset S of [0, 1] such that

bq. For any x in [0, 1] and any c > 0 there exists a member of S such that |x – s| UPDATE: As David notes in the comments, this argument only works against him if it works against Maher. And since Maher has a formal proof that his theory is immune to this kind of counterexample, one might reasonably suspect that it doesn’t work. I _think_ what happens here is that one of Maher’s axioms to which I’d paid little attention rules out this kind of example. But that axiom seems independently questionable, a topic on which I may say more soon. But for now I should just note that since the paper I was commenting on explicitly adopted all of Maher’s axioms, I shouldn’t have proposed a counterexample that didn’t satisfy all those axioms.

Papers

The “papers blog”:http://opp.weatherson.org is not being updated today due to technical difficulties. We should resume normal operations tomorrow.

I’ve had a few requests to do a follow up to the journals survey with a survey/investigation into the turnraround times at various journals. I’m not entirely sure how we’d go about doing that. Relying on feedback from readers could be risky. For one thing, people exaggerate. For another, we tend to remember the worst experiences, not the best ones, so a self-reported selection could be misleadingly bad.

What would be best is if journals made this kind of information publicly available. It might be best just to write to journal editors directly and see if they already post or will make public data on how long it takes on average for papers they receive to get a decision. Any suggestions on better methods of data collection would be appreciated.

My Favourite Puzzle

It turns out that if you let everything else go – blogging, answering email, grading, class preparation, sleeping, etc – it is possible to update a paper. Here’s the latest version of my imaginative resistance paper.

bq. “Morality, Fiction and Possibility”:http://brian.weatherson.org/mfp.pdf

There are several new features.

* I got rid of the most embarrassing examples.
* I added a discussion of Derek Matravers’s solution to the alethic puzzle.
* I added a discussion of Kathleen Stock’s objection to Gendler’s objection to the impossible solution.
* I dropped the claim that imaginative resistance is a feature of _all_ stories with morally deviant content. The data doesn’t support such a strong claim, what with it being entirely composed of short stories or moral claims that are easily detachable from longer stories, so I should never have made it. I’m currently agnostic about whether this stronger claim is true, though I’m tempted to say it isn’t.
* I changed my main theory.

The last bit is probably the biggest, though actually once I saw what I’d got wrong in the original it was an easy fix. Here’s a simple version of the puzzle. Imagine we have a story in which the lower level facts (e.g. the descriptive facts) are inconsistent. For example, we have two descriptions of X’s life, and on the one he always does the just and moral thing, and on the other he tortures children for fun and profit. (I think this is possible in inconsistent time travel stories, but since I’m meant to be neutral about how straight-up inconsistency works in fiction, I have to allow the prospect that it could just be true in the fiction without any trickery.)

So we have inconsistent descriptive propositions D1 and D2, where D1 is the description of a good person and D2 of a bad person. On the original version of the theory, it would have been impossible for any moral claims about the character to be true in the story. “That guy is good and D2” is an asymmetric compound impossibility, so it couldn’t be true. And “That guy is bad and D1” is also an asymmetric compound impossibility, so it couldn’t be true. So we end up with the position that the guy is neither good nor bad in the story. But that’s implausible. What’s more plausible is that he’s *both* good and bad.

Here’s the fix. What causes problems is when we have a higher-level claim (e.g. a moral claim) and the story is such as to exclude any descriptive claims that could ground it. So if it’s true in the story that X is bad, then (in general) there should be descriptive facts in the story that ground this fact. (The parenthetical qualification is that if the story is silent on all descriptive facts about X, it doesn’t need to make the descriptive facts match the moral facts. Sheer silence is permissible.) In this case, since D1 grounds “X is good” and D2 grounds “X is bad”, X is both good and bad in the story, as required. This solves a delicate problem I had to do with the _Fixing a Hole_ example in my paper, and which I had somewhat unfortunately pressed against rival theories without having a solution to offer myself. That sorry state of affairs has passed.

Papers Blog – September 7

The “papers blog”:http://opp.weatherson.org has been updated. Somehow yesterday’s entry, which I clearly and distinctly remember writing, didn’t get posted, so I’ve rewritten it as best I can and posted it under yesterday’s date. If I’ve started having hallucinations about writing entries to the papers blog, that’s a _very_ worrying sign. That kind of thing shouldn’t happen until at least the 10th week of semester, not the 3rd.

And I somehow left off (both entries) the most interesting paper I’ve read online recently, Yael Sharvit’s

bq. “Free Indirect Discourse and ‘De Re Pronouns'”:http://web.uconn.edu/sharvit/sharvit-salt14.pdf

There is a lot of evidence that in free indirect discourse either names or pronouns (or both) are not directly referential. It is a little disturbing to me that given all the attention paid by philosophers to the question of whether names and pronouns are directly referential in standard indirect discourse, philosophers (this one included) have paid so little attention to free indirect discourse, particularly since this data may bear on the original questions philosophers were asking.

Papers Blog – September 7

The “papers blog”:http://opp.weatherson.org has been updated. Somehow yesterday’s entry, which I clearly and distinctly remember writing, didn’t get posted, so I’ve rewritten it as best I can and posted it under yesterday’s date. If I’ve started having hallucinations about writing entries to the papers blog, that’s a _very_ worrying sign. That kind of thing shouldn’t happen until at least the 10th week of semester, not the 3rd.

And I somehow left off (both entries) the most interesting paper I’ve read online recently, Yael Sharvit’s

bq. “Free Indirect Discourse and ‘De Re Pronouns'”:http://web.uconn.edu/sharvit/sharvit-salt14.pdf

There is a lot of evidence that in free indirect discourse either names or pronouns (or both) are not directly referential. It is a little disturbing to me that given all the attention paid by philosophers to the question of whether names and pronouns are directly referential in standard indirect discourse, philosophers (this one included) have paid so little attention to free indirect discourse, particularly since this data may bear on the original questions philosophers were asking.

Keith DeRose

This is just a reminder for those in the area that Keith DeRose will be speaking at Cornell on Friday at 4.30. I’ll post the room and title when I, er, remember them. The talk is in Goldwin Smith – I think G21 – but if you turn up to Goldwin Smith around 4.20 to 4.25 it will be obvious where people are headed 🙂

Back to Imaginative Resistance

Derek Matravers has a proposed solution to the problem of imaginative resistance in his paper _Fictional Assent and the (So-Called) “Problem of Imaginative Resistance”_. I need to write this up more carefully in the future, but here’s the rough sketch of his idea.

Some, not all but _some_, fictions follow the report model. To properly appreciate the story, we must imagine that we are receiving a report from a fairly reliable reporter about some land. The analogy is to how we judge reports from a foreign land by a newspaper reporter. With a newspaper reporter, at least a trustworthy one, we believe what they say when they have an epistemologically privileged position. In the fiction, what we accept are the reports with respect to which the reporter has an epistemically privileged position. The idea then is that the reporter has this privilege with respect to non-moral propositions, but not with respect to moral propositions.

I was going to list a number of objections to this as a solution to the puzzles, but it turns out to be hard to individuate them, so I’ll just make a bunch of points.

The overall theme is that this looks like a restatement of the puzzle rather than a solution to it. Why, we might still ask, does the reporter have privilege with respect to non-moral propositions but not moral ones? The only answer I can see in Matravers’s paper is that (a) that’s how we treat real reports from faraway lands, and (b) the report model of understanding fiction tells us to treat this kind of analogy with foreign reporting seriously. But as far as I can tell, (a) simply isn’t true, so this doesn’t help.

In the following two cases I’ve written a wire report and a short story, and I think you’re going to be able to tell the difference.

bq. “BBC”:http://news.bbc.co.uk/1/hi/england/somerset/3534361.stm – Weston-super-Mare
Children in a nursery were shocked when they spotted a three-headed frog hopping in their garden.

bq. _The Strange Frog_
Children in the nursery were shocked when they spotted a three-headed frog hopping in their garden.

The news report does go on a little longer, and the story could be spelled out, but I think the idea is clear enough. The natural reaction is to *not* trust the foreign reporter, and trust the fictional reporter. It’s hard to see how the report model could explain this. (Hat tip for BBC story: “Language Log”:http://itre.cis.upenn.edu/~myl/languagelog/archives/000567.html.)

For a more dramatic example, compare the following two.

bq. *Earth Under Attack*
When the attack started, the President was two light years away on a campaign trip. But he rushed back to Earth in seven minutes to lead the military response.

bq. _Earth Under Attack_
When the attack started, the President was two light years away on a campaign trip. But he rushed back to Earth in seven minutes to lead the military response.

I trust the fictional reporter, but not the foreign correspondent. This is a fact that needs explaining, and I can’t see anything in Matravers theory that explains it. There is a discussion of how we can end up trusting fictional reporters who assert impossibilities, which one might think generalises. The main point is that impossibilities need to be set up, and the setting up, appeals to Gods or magic or the like, usually establishes the reporter’s privilege. But my stories have no such setup, and yet we accept the privilege.

I’m also not sure how the report model is meant to handle stories that include among their characters real people, but who in the fiction act somewhat differently to how they acted in real life. An expert on those real people, say a biographer or maybe even the person themselves, should for the purposes of the story accept the fictional reporter as being privileged. But they would not take any real person as being privileged.

This all feels like it’s missing the point, that there is some notion of what it is for a fictional narrator to be privileged that is relevant. And I’m prepared to believe there is such a notion. But it hasn’t been given to us yet, for the version we have got doesn’t explain why the fictional narrator gets trusted about the three-headed frogs but the BBC narrator does not. Moreover, the explanation must explain why these fictional reporters can be trusted when they insist they are in counternomic worlds, but not countermoral worlds. And I don’t see the explanation for that.

I also think this doesn’t work as an account of why there can be imaginative resistance in stories not following the report model. In a movie we pretty clearly aren’t seeing a report, but there can still be imaginative resistance to the intended moral message. So at best this could be a partial solution, and in reality I don’t think it manages to distinguish simple counternomic fictions from simple countermoral ones, which is one of the core things a solution to the puzzle has to do.