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. 

Metaphysical and Conceptual Knowledge Connections

Knowledge shows up in theories a lot lately. Or should I say that 'knowledge' shows up in statements of theories? One question I'm hoping to research a fair amount in the near future concerns the status of theoretical claims about knowledge. The knowledge first program, broadly construed, says that knowledge has some kind of priority or privileged status, which makes it a good candidate to explain other states. (My broad construction applies not just to the Williamson project, but to all of those recent projects that posit strong theoretical roles for knowledge, such as the knowledge-action links of Hawthorne and Stanley.) Here's a question I'm interested in: how should we understand the knowledge first attitude? Here are two candidate interpretations:

1. Knowledge, the mental state, is metaphysically (relatively) fundamental; it is among the (more) basic building blocks of the world. Questions about knowledge are questions about the (relatively) natural epistemic joints.


2. KNOWLEDGE, the concept, is conceptually (relatively) fundamental; it is among the (more) basic ideas in our understanding of the world. Questions about knowledge are questions about our (relatively) fundamental conceptual framework.

(The hedges there indicate that knowledge 'first' should surely not be meant to imply absolute priority; one can subscribe, for instance, to the metaphysical interpretation of the knowledge first project and still believe that physical particles are the most fundamental bits of the universe; knowledge is prior to most of psychology and epistemology, perhaps, but not prior to physics.)

My suspicion, which I'm not yet in a position to make good on, is that a lot of authors are fairly indiscriminate about this distinction, and furthermore that it matters. But I'm not at all ready to argue for that claim; I need to re-read a lot of this literature with the question in mind. In this blog post, however, I'll highlight a number of passages that suggest each of the readings. Inclusion on this list is not meant as an indication either that the author endorses one interpretation over the other, or that the author is in any way confused on the matter; this is just a list of passages that strike me as suggestive of one of the two views, so that eventually I can look back and have a whole list of material to scrutinize.

I'll continue to update this blog post as I find passages that appear relevant. Suggestions, of course, are extremely welcome!

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?