The Certainty Norm of Assertion

In a well-known paper, Jason Stanley argues against the knowledge norm of assertion, in favour of a certainty norm of assertion. As Jason notices, knowledge-denying Moore-paradoxes like (1) aren't the only Moore-paradoxes in town; certainty-denying conjunctions like (2) seem similarly paradoxical:

1. Jason works at Yale but I don't know that Jason works at Yale
2. Jason works at Yale but it's not certain that Jason works at Yale

Jason thinks that knowledge doesn't entail certainty, and so a knowledge norm of assertion can't explain what's wrong with assertions of (2). Instead, he opts for a certainty norm of assertion, that's meant to explain both.

The argument I thought I remembered from the paper was that the certainty norm was strictly stronger than the knowledge norm. The certainty norm explains (2) in the obvious way (just like the knowledge norm explained (1)); and it explains (1) by invoking the entailment of knowledge by certainty. If I don't know that Jason works at Yale, it's not certain, so I can't assert the first conjunct. But today I read the paper again, and that's definitely not the argument. Certainty, in the sense Jason discusses, does not entail knowledge.

The relevant notion of certainty here is 'epistemic certainty', according to which 'one is certain of a proposition p if and only if one knows that p (or is in a position to know that p) on the basis of evidence that gives one the highest degree of justification for one's belief that p'. (p. 35) Since certainty does not entail knowledge, on Jason's view, it is not quite clear to me how a certainty norm explains the infelicity of (1). Of course one can't know both conjuncts in (1), but I don't see why why one couldn't have certainty in both conjuncts. Here is Jason's attempt to deal with the issue:

Consider the proposition that there are no large Jewish elephants in my bedroom. This may have been an epistemic certainty for me five minutes ago, even though I did not know that there were no large Jewish elephants in my bedroom. I did not know that there were no large Jewish elephants in my bedroom, because I did not believe it, and I did not believe it simply because it didn't occur to me ever to entertain that possibility. Nevertheless, in this case, if I had entertained the propsition that there are no large Jewish elephants in my bedroom, I would have known it. The reason this counterfactual is true is because it is an epistemic certainty for me that there are no large Jewish elephants in my bedroom. So the fact that a proposition is an epistemic certainty for a person does not entail that the person knows that proposition. If a proposition is an epistemic certainty for a person at a time, then it does follow that the person is in a *position to know* that proposition. Being in a position to know a proposition is to be disposed to acquire the knowledge that the proposition is true, when one entertains it on the right evidential basis. Since epistemic certainty entails possession of this dispositional property, utterances [like (1)] are odd. (p. 49)

The thought seems to be that if something is certain, then if one asserts it, one must know it. But it doesn't follow from his explanations of these notions that this must be so—couldn't something be asserted without being entertained on the right evidential basis? Suppose for instance that p is certain for me, but I don't know p because I am ignoring my overwhelming evidence for p, and basing my belief that p on some bad evidence. Couldn't it be, in this case, that it's also certain for me that I don't know p? I think it seems plausible that I might—my evidence, which, suppose, includes some sort of introspective access to the source of my belief—might overwhelmingly establish that I don't know that p. But if so, the certainty norm predicts that 'p but I don't know that p' should be assertable.

Acting on knowledge under uncertainty

Susan, who is entertaining later this evening, is about to walk to the local market to buy some olives for cocktails. She now faces that famous perennial question whether to take her umbrella. We stipulate:

• Susan does not know whether it will rain during her walk.
• Susan's rational credence that it will rain during her walk is 0.4.
• The nuisance of carrying the umbrella on her walk will cost Susan 10 utils.
• The nuisance of being rained upon without an umbrella is -30 utils. (It is no nuisance at all to be rained on if she has her umbrella.)

It's pretty reasonable to suppose that in this case, Susan ought to take the umbrella; we calculate the expected value pretty straightforwardly. The umbrella costs 10, and gives her a 0.4 chance of saving 30. (30 * 0.4) - 10 = +2. If Susan takes the umbrella in a way sensitive to the positive expected value of doing so, there's a pretty strong intuition to the effect that she's done everything right.

As you know, cases like this one are sometimes thought to be problematic for the knowledge norm of practical reasoning. Alex Jackson's careful paper does a nice job separating different knowledge-norm-like commitments, but he identifies this kind of case as at least a prima facie challenge to the following determination thesis:

What one knows determines what it is rational for one to do (possibly in concert with one’s desires).

I like this determination thesis. (In fact, I like something stronger -- I think we should be after something more like metaphysical grounding, not just determination.) So I need a story about the case of Susan. The Hawthorne & Stanley story is that Susan, if she is acting appropriately, is acting on knowledge about epistemic probabilities. She says to herself: there is a 0.4 chance that it will rain; this thing that she says to herself is what she treats as a reason. And it is something she knows.

I'm pretty uneasy about this line, although I've never been able to put my finger on exactly what I don't like about it. There is something odd, it seems to me, about probabilistic contents playing these kinds of roles. I know that's not an objection; I'm just recording my uneasiness. Here, anyway, is an objection: suppose she doesn't know the relevant probabilistic claim. Suppose that, for all she knows, the chance that it will rain is 0.3.

Remember, this is evidential probability we're talking about; the difference between the chance's being 0.3 and its being 0.4 can't be made by meteorological facts wholly outside Susan's ken. Still, it's not at all implausible that Susan might not know, with that level of precision, whether her evidence probabilifies rain to degree 0.3 or 0.4. Indeed, my own evidence right now, it seems to me, puts the chances of its raining on me as I walk to work tomorrow right around that ballpark; but I have no idea whether it is closer to 0.3 or to 0.4. I hope you agree this is not a very implausible possible situation.

Notice also that if the probability really is only 0.3, then, given the stipulations above, Susan's expected value for taking the umbrella is negative. ((30 * 0.3) - 10 = -1) So under the current stipulations, for all Susan knows, taking the umbrella might have negative expected value. She doesn't know that she should take it. She does, we may allow, know that there is some chance of rain, but this doesn't look like a good enough reason to perform this action.

You might think about trying to gild the bitter pill at this stage, suggesting that if she doesn't know whether it's better to take it, then she really does violate the action norm in taking it, although she does so in an excusable way. This seems to be Hawthorne & Stanley's line. But I don't think we should take it. For it's consistent with our case here that Sarah is exceptionally well-attuned to the evidence. That is, if the chance really were only 0.3, then she wouldn't take the umbrella. This is of course totally consistent with her failure of introspective discrimination.

I think Hawthorne & Stanley were right to look to knowledge with contents other than that it will rain, but wrong to focus in on probabilistic ones, in part for the reason just offered: there's no particular reason to expect them to be known. (And also in part because of that feeling I haven't managed yet to articulate, that these things aren't the right kinds of things to be invoking in one's reasoning.) While there's no reason, it seems to me, to think that Sarah must know the probabilistic content, there is, it seems to me, good reason to think she must have some other relevant knowledge around. If, for example, you think that E=K, then the evidential probability must be probability conditional on some knowledge. Let that knowledge be the reason for action. What is it that is the relevant evidence? I don't know, it depends on how the case is filled out. Maybe something a forecaster said? Maybe the look of the clouds? Whatever it is, I say we understand Susan as acting on the basis of that evidence.

Can you get a case like this involving no such evidence? Alex Jackson tries to give us one. But this blog post is getting long and I'm getting hungry, so maybe I'll leave discussion of that for another day. 

Knowledge, stakes, and closure

I've been sitting in on, and enjoying, Carrie Jenkins's grad seminar in epistemology. Today, one of our grad students, Kousaku Yui, brought up a pretty interesting suggestion in response to Jason Stanley's stakes-relative approach to knowledge. I didn't recognize the point as one that I've seen discussed before -- if there is a literature on it, I'd be very interested to see it.

The worry is this. Jason thinks that when the stakes are high, it's harder to know. But stakes aren't just a feature of an individual at a time; stakes are high for certain propositions when the truth or falsehood of those propositions make a big difference. It's possible to be such that the stakes for p are high, but the stakes for q are low. For example, it may be very important to Hannah and her wife Sarah whether the bank is open tomorrow, but not at all important to them whether it will rain tomorrow. In such a case, they would need to meet more exacting 'standards' in order to know about the bank than they would to know about the rain. That's a little bit counterintuitive, but only in the way that pragmatic encroachment is generally a little bit counterintuitive.

But here's what might be a deeper problem. Suppose someone is in a situation like the one just mentioned -- the stakes for p are high, but the stakes for q are low -- but where the subject knows that if q, then p. If so, then it's easy to know q, but hard to know p; but it looks like anyone who knows q could easily infer p. Closure plus the possibility of a case with this structure looks like they entail that the stakes-sensitive view can't be right.

Do we have to say such cases are possible? I don't see anything that forces us to, but certain cases are very naturally described in that way. Suppose Hannah and Sarah have an important bill, as per the standard high-stakes bank case; it's very important to them whether the bank will be open on Saturday. Suppose also that they have a friend Franklin who is a bank teller, and they have some small interest in whether he will be at the bank on Saturday. Here, however, the stakes are low -- nothing much hangs on whether they're correct about Franklin's location on Saturday. Assume that they have a good enough position for arbitrary strong knowledge standards for the proposition that Franklin will be at the bank only if it is open. So we have:

• p: The bank is open Saturday


• q: Franklin is at the bank Saturday


• The stakes for p are high


• The stakes for q are low


• Everyone knows that if q, then p.

If Hannah and Sarah have a middling epistemic position with respect to q, then it looks like they're in a position to know q, but not to know p. But this violates closure.

Might Jason say that in such a case, the high stakes for p force the stakes up for q as well? He might, but it seems like a pretty strange thing to say. Intuitively, it doesn't matter to them much at all whether Franklin is at work on Saturday. Their bill situation has nothing to do with Franklin. Maybe we can wrap our heads around the idea that the bill makes it harder to know that the bank is open -- but can it really make it harder to know where their friends are?

Conditional knowledge attributions

I'm going to be discussing an argument that I know Jason Stanley to have given, but I'm away from my copy of his book at the moment, so I can't cite it properly, or check and see who else has discussed it (or even whether it's original to Jason). I'll follow up if citation protocol ends up demanding it.

Here's a naive argument against 'knows' contextualism. (This isn't the Stanley argument I want to discuss; it's part of the set-up for it.) Assume contextualism. Now suppose you're in a nonskeptical context, and I'm in a skeptical one, and we're both talking about me and the proposition that p, a proposition with which I stand in a pretty strong epistemic relation -- one strong enough for your non-skeptical 'knows', but not for my skeptical 'knows'. You say: "Jonathan knows p." Now, according to this naive objection, I'm forced to say this:

(1) I don't know that p, but what you said was true.

This sounds like a crazy thing to say, under the circumstances, but it looks like contextualism predicts that it should be fine.

Of course, contextualism doesn't predict that (1) should be fine; the naive objection is naive. Contextualism avoids the felicity of this utterance by observing that it won't be assertable for me. What you said entails p (even your nonskeptical 'knows' is factive). Since I'm not in a context in which "I know that what you said is true" is true, I therefore can't assert that what you said is true. Indeed, (1) is Moore-paradoxical, or near enough, since it straightforwardly and transparently entails "I don't know that p, but p."

So there's a naive objection to contextualism and a good response on the contextualist's behalf. But Jason Stanley thinks the game isn't over yet, for he has a tweak on the objection to make it less naive in a way that he thinks will avoid the response. Take the same set-up as before; you're in a non-skeptical context and you say "Jonathan knows p," and I'm in a skeptical context where "I know p" is false. Now, Jason asks, why shouldn't I give this sentence?

(2) I don't know that p, but if p is true, then what you said is true.

Here, the second conjunct doesn't entail that p, so the sentence isn't Moore-paradoxical. Insofar as (2) also sounds crazy, we have a version of the objection that isn't susceptible to the quick response given above. (Does (2) sound crazy? Is it a natural enough sentence to generate clear intuitions? I don't know. Let's grant for the purpose of argument that it sucks to have to render this sentence assertible.) The contextualist, I contend, is not committed to the assertibility of (2). Although (2) is not Moore-paradoxical, because the second conjunct does not entail p, its infelicity can still be explained as a violation of the knowledge norm of assertion, since it's second conjunct will, in the relevant cases, be unknown.