Wednesday, May 21, 2008


Lackey on Moore's Paradox

I've been reading Jennifer Lackey's new book 'Learning from Words' in preparation for meeting her this weekend, and I've really enjoyed it so far. It's superbly written, and it's both a useful overview of the main issues at stake in the recent debate over testimony, and an interesting and original contribution to that debate. The book is based on a series of papers Lackey has published since 1999, but it's useful to have the material collected together, and there's a significant amount of new stuff and revision.

Here I want to raise a worry about her explanation of Moore-paradoxical sentences in the chapter on norms of assertion. Williamson, taking his cue from Unger, has noted that the knowledge account of assertion offers a particularly elegant account of why there's something wrong with asserting sentences of the form 'p, but I don't know that p'. But an issue immediately arises about what it is that needs explained. Here are three answers that one might endorse:

1. The usual answer is that what needs an explanation is why we hear assertions of such sentences as contradictory or paradoxical, despite the sentences themselves being perfectly consistent.

2. Following DeRose's influential '92 paper on epistemic possibility, some participants in the debate have suggested that all that we need to explain is why such sentences sound odd. (See Douven's 2006 Phil Review article, for instance.)

3. Lastly, we might think that all that really needs accounting for is that such sentences ought not be asserted.

It seems that the tasks involved get less demanding as one moves from (1), through (2), to (3). And, relatedly, it seems like to have successfully carried out one of these tasks is also to have carried out the tasks below it, but not above.

So what does Lackey take to require explanation? It seems that she initially takes it to be (1). Here's how she introduces the topic:

'Moore famously noted that assertions of these general forms--that is, of either the form "p, but I don't believe that p" or of the form "p, but I don't know that p"--seem quite paradoxical.' (130)

It is this paradoxicalness that Lackey takes Williamson and other proponents of the knowledge account (KNA) to trying to explain:

'Advocates of the KNA are in an excellent position to account for the paradoxical nature of asserting Moorean sentences.' (130)

Lackey wants to defend a rival to the KNA, the reasonable belief account. Moorean sentences seem to be a problem for this account, since Lackey herself has described cases in which it is reasonable for a subject to believe p, and that they don't know p. These are cases of selfless assertion, in which a subject asserts p on the basis of great evidence - evidence which makes it reasonable for her to believe p - and yet isn't willing or able to bring her beliefs into line with the evidence, and so either fails to form any belief on the matter, or continues to believe ~p.

In response, Lackey argues for a second norm, the NMNA, which rules an assertion as improper if it is reasonable for the asserter to believe that it will be misleading in the context of utterance. (She suggests this second norm might get subsumed by Gricean maxims; I think it would strengthen her position if she were so.) It's the NMNA that allows her to deal with Moorean assertions:

'the NMNA rules out the permissibility of asserting such paradoxes in most circumstances, even when they involve selfless assertions,' (134)

How? Well, consider one of Lackey's examples of selfless assertion. Sebastian is a well-respected doctor who has seen excellent evidence showing that there's no link between vaccinations and autism. However, his own child was recently diagnosed with autism not long after receiving vaccinations. As a result, he cannot bring himself to believe that there's no connection, despite recognizing that the evidence all points in that direction (he recognizes that the case of his own child isn't evidence to the contrary, and that his reluctance to belief that there's no connection stems from his emotion state). When asked by a patient whether there's a connection between vaccination and autism, he sets his own feelings to the side, and asserts on the basis of the excellent evidence that there is not. Of this case, Lackey writes:

'such an assertion is most likely to lead Sebastian's hearers either forming no relevant beliefs at all, because they are confused by its oddity, or to forming false beliefs, because they are trying to plausibly explain its oddity away.' (134)

Notice the shift. Not only are we now engaged in task 3 rather than task 1, Lackey's account, far from providing an explanation of the oddity of assertions of Moorean sentences (task 2), actually helps itself to the fact they sound odd in order to explain why they should be ruled impermissible by the NMNA.

Now, it may be that Lackey conceives of the challenge to the reasonable belief account as follows; the account rules as permissible assertions which strike us as paradoxical and/or odd. But if so, we should wonder why this lack of ambition wasn't flagged more clearly, and we should wonder whether we can rest content with an account of assertion that can only help us with such an unambitious (type 3) explanation of the Moore cases, when there are rival accounts which enable us to offer type 1 and type 2 explanations.

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Hey Aidan,

This is slightly off topic, but there's something that bugs me about Lackey's criticism of the knowledge account. First, I'm not sure that her cases of selfless assertion are cases of assertion. (Or, if they are assertions, I'm not sure their content is quite what we might think initially.) Her examples all involve people in professional roles whose roles require them to say things they need not believe. I just don't see why we don't say that in virtue of their roles we either interpret them as asserting claims about what ought to be asserted by people in those roles (things the speakers actually know to be true) or take them to be doing something other than asserting altogether. For one, you cannot even accuse them of insincerity for uttering 'p' without believing p, and that is very much unlike ordinary assertion. Second, I'm not sure why the knowledge account cannot just say that what matters is that the belief is known by someone or other much in the way that the RBNA does.

(I've also found her criticism of the truth requirement particularly unconvincing, but that's another matter.)
Hi Clayton,

I'm not convinced by Jennifer's cases either, but let me play devil's advocate a little.

You are right that all of the examples involve people playing a particular role. But the case of the racist juror is a little different, since his assertion is made to a friend, outside the courthouse. He's already discharged his role. One might think he's trying to assert on the basis of the evidence rather than on his own screwed up belief, and that this has nothing to do with any professional role.

(Your other point about sincerity and assertion is interesting, but I'm too burnt out tonight to think it through. Hopefully I'll get a chance to come back to it.)
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