Thanks to everyone for sharing their intuitions about the cases in my previous post. Here I’m going to back up and say something about my interest in the cases. Among linguists, the canonical view about modal expressions like “might”, “may” and “must” is that they are quantifiers over possibilities where the domains of quantification are contextually restricted. The view is an extremely powerful one; if correct, it provides a simple, highly unified explanation of a wide variety of language use. Recently, the canon’s neat story has come under attack on two fronts, in its treatment of bare epistemic modals (BEMs) and bare normative modals (BNMs). (A bare modal statement is a modal statement that doesn’t contain a restrictor phrase like “in view of my evidence” or “in view of what the law requires”.) I’ve got a manuscript defending a general, flexible contextualist account of bare modal statements and an application of that account to BEMs. (Here: http://www.unl.edu/philosop/people/faculty/dowell/dowell.shtml) Now I’m working on defending an application of that account to BNMs. (NB: My apologies in advance; this post is both long and oversimplified.)
The puzzle cases for contextualism about BNMs focus on apparent disagreement across contexts. On the canonical contextualist account, modal statements are doubly relative; they have two parameters that context must provide a value for. On the view I’m defending, one of those parameters is set either by a contextually determined body of information or set of circumstances, the other by contextually determined standard.
Here's the basic puzzle case for apparent disagreement across contexts shifting the value for the information parameter:
Imagine a doctor deliberating about which of three drugs, X, Y, or Z to prescribe a patient to relieve the symptoms of her skin irritation. Doctor’s limited information suggests that X and Y each will provide complete relief, while drug Z will provide only partial relief. In light of this, she asserts:
Doctor: (X) “I ought to prescribe either X or Y.”
Suppose a consulting physician has more information about the patient’s medical history and each of the drugs than Doctor does. In particular, Consultant knows that while it is true that, absent any interfering drug already in the patient’s system, either X or Y would provide complete relief, it is also true that Patient is already taking drug W which, together with one of either X or Y, is certain to kill the patient. (Consultant knows that, given that the patient is taking W, exactly one of X or Y will kill her and the other completely cure her, but she does not know which drug would have which effect; each is equally likely to be the lethal drug.) Z, in contrast is certain to provide some relief and certain not to have any negative side effects. Given this, Consultant replies
Consultant: (Z) “No, it is not the case that you ought to prescribe either X or Y; you ought to prescribe drug Z”.
We can sum up the expected outcomes, given the information of the Doctor and Consultant, respectively, this way:
Drug X Drug Y Drug Z
Doctor: 1.x complete cure 1.x complete cure 1.x partial relief
Consultant: .5 x Death + .5 x complete cure .5 x Death + .5 x complete cure 1.x partial relief
The question is: How can a contextualist capture the sense we have that Doctor and Consultant are giving different and incompatible answers to a common question? If each of (X) and (Z) is relativized to the speaker’s information, then Doctor and Consultant are not disagreeing and Consultant’s assertion is not an answer to the same question as Doctor’s. But since Consultant’s “no” is felicitous, Doctor and Consultant do seem to be disagreeing. Moreover, Consultant seems to be advising Doctor by aiming to give a superior answer to the very question Doctor aims to answer with (X).
The puzzle rests on an assumption about which value a contextualist account holds that context selects, namely, that context selects for each of (X) and (Z) the information the speaker possesses at the time of utterance. If that’s right, then Doctor and Consultant are neither disagreeing, nor addressing a common question.
On the flexible, contextualist account I favor, which value for each of the parameters is contextually selected is determined partly by a speaker’s extension-determining intentions, i.e. publicly manifestable intentions to let some feature of the context settle the restrictions. I understand the intentions here dispositionally, as a disposition to recognize some feature of the context as restriction-settling.
The beginning of wisdom then is to note exactly what is puzzling about the case, given the presumed contextualist treatment. Let t3 be (roughly) the latest time at which Doctor can effectively prescribe a drug. Let t1 be the time at which Doctor asserts (X) and t2 the time Consultant asserts (Z). On the contextualist treatment presumed in the puzzle’s statement, a speaker is asking herself “which act is best performed at t3 given what I know now?” Interest in that question would be surprising, because Doctor finds herself in a context of deliberation and, as Finlay and Bjornsson note in their manuscript on this topic, deliberators tend to be news-sensitive. I think of news-sensitivity dispositionally, as a readiness to revise one’s judgment about what one ought to do in light of new information. Given that deliberators, at least when they are rational, are typically news-sensitive, it would be odd if Doctor were interested in which act would be best at t3, given what she knows at t1, only to abandon her interest in that question, should new information come to light prior to t3. If Doctor is news-sensitive, it is better to understand her as intending to speak to (something like) the question “what ought I to do at t3 given the information I’ll have then?”
On my account, in the puzzle case, Doctor and Consultant are disagreeing about how to answer that very question. Let’s assume that Doctor has at t1 a reasonable opinion about which body of information that that is, namely, that it’s the information she possesses then. Then (X) is warranted, though false.
This analysis generates a prediction about cases of hindsight evaluation that I wanted to test with the first of my two cases in my previous post. The prediction in that case is that we won’t think of better-informed, hindsight evaluators as warranted in disagreeing with deliberators who did the best they could with the information available at the time of action. And that prediction was rather overwhelmingly borne out by the reactions that I got from Pea Soup commentators and others (some philosophers, some careful ordinary speakers). A strong majority found either Sp to be the best response or tied with Gp. Among the remaining group, there was a majority preference for Gp or the view that all except Dp were acceptable. No one ranked Dp or Fp as better than both Sp and Gp. An even larger majority found Dp unacceptable and, most of those found Fp also unacceptable.
This is just what we should expect on the account I defend. “I disagree” clearly expresses an attempt to reject the whole modal claim in (Z) and (Z’). “That’s false” is less clear, but can be heard in the same way. “That’s a shame”, in contrast, is an expression of regret that may signal a context-shift, as it does in Gp. Sp explicitly expresses agreement with the whole modalized claim in (Z) and (Z’), as is warranted on my account. Interestingly, many who stuck up for either Dp or Fp did so by insisting that they are semantically appropriate, though either silly or false. This is also the right thing to say on my account, which distinguishes between norms of assertion that govern linguistic appropriateness and those that govern warrant. Added bonus: solipsistic relativism predicts that Dp is not only appropriate, but warranted and true. So, it conflicts with this response pattern.
The Pea Soup comments on my second case helped me see that my characterization of the case needs improvement. The case that I described was both too vague and too friendly to the contextualist. Thanks to everyone for their help with both cases.