Tuesday, February 26, 2008

 

When you're tagged, you're tagged....

"Air pollution is indeed a significant health threat in the former socialist economies, where decades of inefficient production still takes its toll. Nevertheless, apart from the risk of unsafe sex and illicit drugs, even here the pollution risk of 3.5 percent YLL is the smallest of the industrialized world risks. And when we look at the OCED-area, it becomes obvious that at 0.6 percent the environmental risk from air pollution is by far the smallest of all OCED risks."

This is from p123 of Dan Bonevac's Today's Moral Issues. I'm Dan's TA again this semester, and the tag caught me preparing for this week's discussion sections.

Anyways, thanks Shawn. I guess I need to pass on the favor, huh. Well, no real pressure guys, but I'll go for:

Errol,
Neil,
Bryan,
Aaron and
Flic

Here's your instructions:

1. Grab the nearest book (that is at least 123 pages long).
2. Open to p. 123.
3. Go down to the 5th sentence.
4. Type in the following 3 sentences.
5. Tag five people.

I'm unclear on what the point of this exercise is supposed to be - I guess it's meant to be revealing in some way.

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Monday, February 18, 2008

 

Student types

I can't resist linking to Jon Cogburn's updated list of student types. If you've ever led a philosophy discussion section, this will all sound awfully familiar....

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Testing for Context Sensitivity (Part 2)

I think Bryan was probably right in his criticisms of my last post on this topic, but let me post some further thoughts on Cappelen and Lepore's tests for context sensitive. In a footnote on page 101, they give us the 'VP-ellipsis test'. But their discussion of this test has always struck me as somewhat bizarre.

Here's the test in short. Context sensitive expressions have fixed interpretations under VP-ellipsis. So if an expression has a fixed interpretation under VP-ellipsis, it's context sensitive, otherwise not.

This seems initially very surprising. One would have thought that context insensitive expressions also had a fixed interpretation under VP-ellipsis. But Cappelen and Lepore write:

'noncontext sensitive expressions do not exhibit this feature, as in

John bought a car, and so did Bill.' (101fn7)

But here the supposedly context invariant expression is the quantifier expression 'a car' - hardly a good choice of an uncontroversially context invariant expression.

(I'm taking it that 'noncontext sensitive' just means context insensitive here. Let me know if that's wrong).

A page over (102fn8) they suggest that Stanley is hoist by his own petard, since he employs the VP-ellipsis test to argue that vague expressions aren't context sensitive, failing to realize that the test tells against his own treatment of quantifier domain restriction. This isn't the first time I've encountered this interpretation of Stanley's argument, so I think it's worth pointing out it's badly mistaken. Stanley never uses the VP-ellipsis test, and in fact, he never argues that vague expressions as a class are context insensitive. Rather, he argues that even if they are context sensitive, that doesn't serve to offer a unified solution to the Sorites paradoxes. He takes contextualists to be making the claim that vague expressions are indexicals, and constructs instances of the Sorites which employ VP-ellipsis to fix the interpretation of the vague expression in question throughout the series. The contextualist about vagueness wanted to disarm the reasoning driving the Sorites whilst explaining why we find it so compelling, and Stanley's objection is that the contextualist's story, in terms of context shifts as we run through the series, has limited scope.

So Stanley doesn't use the VP-ellipsis test to argue that vague expressions are context insensitive. That's a really bad interpretation of his argument. Rather he uses the fact that indexicals have a fixed interpretation under VP-ellipsis (a couple of tricky examples such as the now famous A - 'I love you', B - 'I do too' exchange aside) to enable him to construct instances of the Sorites which contextualist accounts of vague expressions (or at least those according to which they are indexicals) can't disarm. And since the claimed fact is explicitly restricted to indexicals (and demonstratives), we needn't expect quantifier expressions to behave similarly.

So let me boldly state my conclusion: the VP-ellipsis test provides no test for context sensitivity, and it is powerless against Stanley's acccount of quantifier domain restriction. Right?

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Wednesday, February 06, 2008

 

Does Knowing Figure Ineliminably in Causal Explanations?

In chapter 2 of Knowledge and its Limits, Williamson argues that in some cases 'reference to states of knowing is essential to the power of a causal explanation' (63). He notes that in order to prove that this held for a given causal explanation 'one would need to show that [the reference to states of knowledge] could not be eliminated in favour of any combination of believing, truth, and so on' (63). So instead of providing such a proof, he offers a general recipe for countering such suggestions:

'Given a potential substitute for 'knows', suppose that it does not provide a necessary and sufficient condition for knowing. One then constructs possible cases in which the failure of necessity or sufficiency makes a causal difference, making the proposed substitute not even causally equivalent to knowing. The potential substitute avoids this problem only if it does provide a necessary and sufficient condition for knowing.' (63)

So suppose one substitutes 'believes truly' for 'knows' in some causal explanation. To take Williamson's example, we can ask why a burglar spent the entire night ransacking a house, given that he increased his risk of being caught the longer he stayed. Start with the explanation that he knew that there was a diamond in the house. If we merely say he truly believed that there was a diamond in the house, we give a worse explanation of why he stayed so long, risking detection. For suppose he truly believed that there was a diamond in the house because he had been told that there was a diamond under the bed, when in fact the only diamond was in a drawer in the study. In that case, it seems he would be likely to give up his search after looking underneath the bed, having given up his true belief that there's a diamond in the house. Williamson now argues:

'Given suitable background conditions, the probability of his ransacking the house all night, conditional on his having entered it believing truly but not knowing that there was a diamond in it, will be lower than the probability of his ransacking it all night, conditional on his having entered it knowing that there was a diamond in it. In this case, the substitution of 'believe truly' for 'know' weakens the explanation, by lowering the probability of the explanandum conditional on the explanans.' (62)

If we try to get around this point by substituting 'believes truly without reliance on false lemmas', we can construct a scenario where the burglar's true belief does not rely on false lemmas, but he receives misleading evidence in the course of his search, which makes it less probable that he would risk staying the entire night than if he knew that there was a diamond there (63). We could switch to 'believes truly without reliance on false lemmas and with stubbornness in one's belief in the face of counterevidence', but then, since such stubbornness is not necessary for knowledge, we can find an alternative cases in which the failure of necessity for knowledge makes a causal difference. And so on; for each proposed substitute for 'knows', there will be an argument that that substitute doesn't cut it.

Frank Jackson has a paper offering a response to this argument (which I think is appearing in Duncan Pritchard and Patrick Greenough's Williamson on Knowledge volume with OUP), but I have a different worry. I'm just not sure with what right Williamson can assume that for any substitute which does not provide necessary and sufficient conditions for knowledge, there will be a possible case in which 'the failure of necessity or sufficiency makes a causal difference, making the proposed substitute not even causally equivalent to knowing'. That seems to beg the question against someone who wants to maintain that reference to states of knowing are not essential in a given causal explanation; it's just an assertion that any non-equivalent substitute can't be causally equivalent.

So far I've been arguing that a crucial premise in Williamson's argument for the essentiality of reference to states of knowing in some causal explanations is question-begging; it's just an unwarranted assumption that any substitute for 'knows' which does not give necessary and sufficient conditions for knowing cannot be causally equivalent, and I don't see why Williamson's opponent should grant that. Without that premise in place, I don't see how consideration of a few cases suffices to get us to Williamson's conclusion. But clearly my point here would be much stronger if one could show that premise to be not just under-motivated, but actually mistaken. I think Williamson's own account of knowledge provides materials for one attempt to show this.

Williamson holds that knowledge requires safe belief; that is, the following subjective conditional must hold:

Safety: Bp -> p

(In words: in the closest worlds in which you believe that p, p is true: your belief could not easily be false)

Now suppose our burglar enters the house with a confident, true belief that's not based on any false lemma that there's a diamond in the house, but that belief is unsafe. Now, how do we continue the case so that the failure of his belief to be safe makes it more likely that he'd leave the house before morning than if he knew? The relevant difference between him and his counterpart who knows is just that the modal space around them is different. I don't see how to continue the case so that this modal fact makes the kind of causal difference Williamson needs it to.

I don't mean to suggest that Williamson holds that knowledge is just confident, safe, true belief. Of course he'd reject this analysis of knowledge, just as he'd reject any other. Williamson writes, 'the search for a substitute for knowing in causally explanatory contexts is forced to recapitulate the history of attempts to analyse knowing in terms of believing, truth, and so on, a history which shows no sign of ending in success' (63). Though I'm not as pessimistic as Williamson on this score, I take the point. It is going to be very hard to specify the right substitute for 'knows', without just describing it as 'knowledge minus safety'.

But the general point I've tried to make should be clear despite these - admittedly difficult - complications; once we add modal constraints such as safety onto knowledge, it becomes hard to see how on what grounds we should hold that any substitute which does not give sufficient conditions for knowledge must fail to be causally equivalent. And that's a crucial premise in Williamson's argument that reference to states of knowing are essential in some causal explanations.

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