Ridiculous Assertors

John Hawthorne gives the following example:

I ask S whether she agrees that P. She asserts that she does: “Yes,” she says. I then ask S whether she realizes that Q follows from P. “Yes, ” she says. I then ask her whether she agrees that Q. “Im not agreeing to that,” she says. I ask her whether she now wishes to retract her earlier claims. “Oh no,” she says. “I’m sticking by my claim that P and my claim that P entails Q. I’m just not willing to claim that Q.” Our interlocutor now resembles perfectly Lewis Carroll’s Tortoise, that familiar object of ridicule who was perfectly willing to accept the premises of a modus ponens argument but was unwilling to accept the conclusion…

This example is supposed to provide an argument for a closure principle about knowledge, in some way depending on the idea that you aren’t supposed to assert what you don’t know to be true. I don’t see how to reconstruct the argument using this knowledge norm, but that’s not the point I want to pursue here.

Instead, I want to consider whether we can expand the above case so that S turns out not to be a ridiculous assertor, but a sensible one. If we can, we won’t have shown that closure is false, but we will have undermined any simple argument from S’s ridiculous stance here to a closure principle.

So suppose S thinks about epistemology on occasion, and thinks there is an order of knowledge among types of knowledge claims. She thinks, that is, that some things can’t be known on the basis of other things. She isn’t sure whether there is a way of ordering claims, even a partial ordering, so that we can always say what has to be known before what. So she sticks with the negative characterization of epistemic priority just given.

She’s talking with Dretske. He says to her, “Is that a zebra?”, and she says, “Yes”. Dretske says, “Do you realize that it can’t then be a disguised mule?”, and she says, “Yes,” again. Dretske smiles, but Hawthorne is perturbed. He taps her on the shoulder, with the verve of expression characteristic of his nature: “so it’s not a disguised mule, right?” She says, “I’m not comfortable saying that yet. I can see it’s a zebra, and that this implies that it’s not a disguised mule. But I can’t learn that it’s not a disguised mule like that. And now that Fred points out the implication to me, I’m unsure of how or whether I know that it’s not a disguised mule.” Hawthorne then says, “So, I take it, you’ll want to retract one of your earlier claims.” “No,” she says, “I’m not questioning whether it’s a zebra–it is, I saw it–but I’m not sure I should be claiming that it’s not a disguised mule, since I can’t know that claim by inferring it from the zebra claim, and without knowing it in that way, I’m really not sure how I know it at all. So I think for now I should just remain silent on the point until I get this figured out a bit better, or until I go check to make sure it’s not a disguised mule.” John presses a bit: “You do agree that it has to be a non-mule, right?” “Yes, but I hesitate, not because the claim might be false, but because I’m not sure I’m entitled to be saying anything about it at this point.”

The point of expanding the story in this way is this. S is not a ridiculous assertor in this story. She is confused and there are various possibilities to explain how she can sensibly find herself in this predicament. One is Dretske’s explanation that closure is false; another is that closure is true, and she’s presupposing the idea that you shouldn’t assert a claim when you’re not sure that, or how, you know it to be true. Whatever the explanation, however, one can’t accuse her of being like Lewis Carroll’s tortoise, and so one can’t infer from the expanded story that denials of closure are somehow incompatible with the practice of non-ridiculous assertion.

There’s a quicker way to put this point, if you’ve read Stew Cohen’s piece on easy knowledge. In the expanded story, S is bothered by the problem of easy knowledge and so ends up talking in a way that may look like a denial of closure. Since there are other plausible ways of making sense of her responses that don’t require a denial of closure, there’s no reason from the sensibility of her responses here to deny closure. But neither is there a good reason to say that she is a ridiculous assertor, and take that as evidence for closure.


Comments

Ridiculous Assertors — 8 Comments

  1. Very nice example Jon, I wonder if there isn’t another story expansion which would achieve essentially the same result in a broadly Foleyesque way. Suppose I’m worried I’ve walked into a paradox. You ask me “Does one piece of grain constitute a heap?” I quickly answer, “Of course not!” Then you ask, “Does one piece of grain ever make the difference between a non-heap and a heap”? “No” I say. You smile. Next you ask me, “Is that a heap of grain?” I casually glance at the heap of grain and say “Yes, of course.” Your grin widdns. At last you explain the sorites paradox to me–that it follows from my first two admissions that there are no heaps–and ask if I now want to take back any of my previous answers. I think it’s very non-ridiculous–in the grip of a paradox–to stick to one’s answers until one understands the situation better.

    My answers sure *seem* inconsistent to me, but they still all seem individually true to me as well. Perhaps I think I’ve been tricked or am missing something or that there’s some super-duper logical maneurver which will show that they are consistent after all. In any event, I think there will be lots of ways of telling the story with the result that people in the grip of a paradox ought to sit tight on their assertions even though they seem to violate closure.

    Just a quick word on “violating closure”. I’m not sure what this means, but it gets used a lot. I’ve expressed previously on CD the idea that statements about epistemic closure are most useful if person-indexed: Timothy is such that the closure under competent deduction of the set of propositions known by him is a subset of the things known by him. This is manifestly not true of Trent. This allow us economically to say certain things about people’s reasoning abilities for example and, as I say in a previous post, it can even be used to express my epistemic responsibility (what closure principles should I satisfy) or my epistemic goals (what closure principles I aim to make true of myself). But if people are thinking that there are statements of closure that will hold for all actual cognitive agents, that seems highly unlikely to me. When I hear a closure principle, I want to know exactly to whom it is supposed to apply and if it is supposed to be indicative or normative (in addition, of course, to the base set and the relation in question).

  2. Trent,

    A sorites is a very good illustration. Unlike the example Hawthorne uses, we can reasonably disagree over the logical structure in sorites. You can in short be unsure what should be added/subtracted from the propositions you’re committed to. You might reject your premise 2 supervaluationist style for instance holding that no matter how you precisify your language, there is some grain that makes all the difference, but there is no non-arbitrary way to precisify or epistemicist style holding that there is some grain that makes all the difference but we couldn’t know what it is or, . . .or.
    But I am not sure why this matters to Hawthorne’s point, if I am tracking it. Wouldn’t he just say, “I am talking about cases where the logic is clear, cases where you can’t get off the hook because the logic of the case is muddy. Of course, if we’re not sure of the logic, then we won’t know what other propositions we’re committed to. But that doesn’t show that it isn’t silly to deny those commitments when the logic is clear.”

  3. Mike, you raise a good point. To address that point I’d suggest first that at the very least I think it shows that there’s yet one more item that needs to be added to the ever-increasing set of caveats required to obtain a plausible closure principle.

    My main point is that the the-logic-is-unsure case is just a particular example of the what-the-hell-is-going-on type of case. I think that the point applies to paradoxes generally (where I’d characterize a paradox generally as an argument from apparently clearly true premises to an apparently clearly false conclusion via apparently clearly true inferences). That is, I think that it’s likely to be true in general that when one finds oneself confronted with a paradox, even if you’ve no idea what the next move should be, you are not to be faulted for taking a wait-and-see attitude (though I would criticize someone who sat still for too long when they had leisure to investigate).

  4. It is a great case, and I think that Jon is fundamentally right about it. It’s important to note, though, that S had to have _something_ to say in defense of her position on the entailed proposition. Asserting p, and asserting that p entails q, does indeed place a burden on one with respect to q. Sometimes that burden can be met via p and p->q themselves; sometimes it can be met with independent evidence for q; sometimes it can only be met with the kind of sophisticated tapdancing of the sort described in Jon’s case. And sometimes it cannot be met at all, and one must abandon at least one of the initial assertions.

    This all suggests a different closure principle than one involving knowledge. Let us call the propositions that we must be able to say _something_ about, even if it is of a tapdancing sort, and which we can say that requisite something about, the set of _defensible_ propositions (for a person, at a time). Is it perhaps the case that the set of defensible propositions (for a person, at a time) is closed under entailment? Or at least under known entailment?

  5. Jonathan, that’s a nice idea, the idea of closure for defensible propositions. My first thought about it is that there will be complications arising from defeaters, since one could need to say something about both p and ~p, given conflicting evidence. Any ideas there?

  6. Maybe a case involving modal knowledge. Lots of people are less confident in their beliefs about what is possible than they are in their beliefs about what is necessary. Bill Rowe gives this nice example. If there is a maximally great being then it is impossible that you are in less-than-perfect company. But it does seem possible that you are in less-than-perfect company: i.e. if modal intuition counts for anything, there seem to be worlds in which every being has some minor flaw or other. So you might have a terrific argument for the view that there is a maximally great being and (given other worries about modal knowledge) hesitate over the possibility that everything in some world has a minor flaw. You’re just not so sure how accurate your intuitions are about what’s possible.

  7. Jon, I’m not entirely sure I’m getting your concern — could you give a slightly more filled-in example?

    Your comment does suggest to me that I need to clarify the ‘saying _something_ about’ relation at least a little, in the following way: if you are arguing that p, and someone objects to you that r, where r is incompatible with p, then there is a sense in which you need to say something about r. But what you really need to do is say something _against_ r (or, of course, against r’s incompatibility with p). In the sense I’m waving my hands at here, it would be more appropriate to say that you have to say something about not-r, than that you have to say something about r. Let me officially change the formulation from ‘say something about’ (which does seem to include propositions that one is defending oneself against) to ‘say something on behalf of’ (which, I hope, does not).

    Now, it’s important that S be able to on many occasions remain pretty neutral on a proposition like r — to say just enough to keep the objection away, but not nearly so much as to constitute even a weak endorsement of not-r. So among the possible things that can count (on some occasions, for some propositions, in some contexts, for some person at some time, etc.) as ‘saying something on behalf of not-r’, we would need to include some fairly weak candidates, like ‘contending that not-r is basically consistent with the available evidence’.

  8. Jonathan, sorry for the lack of explanation above! And I’m not sure there’s an issue here at all, but here’s what I was thinking. If, somehow, both p and ~p end up in the relevant set that is closed, it will be difficult for the set to exclude any propositions at all. That set, if per impossible there could be one, is of course closed. But we want to avoid identifying the set of defensible claims for a person with that set or collection.

    Your comment about how to understand “saying something about” may get us out of the problem. But suppose you have evidence against p and for p. In conversation, I point out the evidence against; now you have to say something as to why you don’t believe ~p. Had I pointed out the evidence in favor of p, you would have had to say something about why you don’t believe p. That looked to me like you’d end up with both p and ~p in the set, and then, if we behave classically, we can derive anything and you’ll have to say why you don’t believe it.

    Given what you say above, this issue may disappear since you focus on logical incompatibility before being forced to say something about a claim.

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