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23 August, 2006

Doxastic Voluntarism

There are several questions about the relationship between belief and voluntariness that I’m planning to write about over the upcoming months. Several of these topics will be pretty familiar, but some might not be. (I’m interested in the role that doxastic voluntarism, or something like it, plays in Meditation Four, for instance, which is not as far as I can tell one of the big topics on the radar screen in contemporary philosophy.)

But those are for more serious posts. Today I just want to make a little observation. Philosophers often write as if it is obvious that we can’t decide to form beliefs. You might think that if this is obvious, then authors would never have characters, let alone narrators, decide to form beliefs. But if you did you’d be very badly mistaken.

For what it’s worth, I suspect the psychological assumptions these authors are making are quite plausible. When someone tells us something that is plausible, but not such that we should obviously trust them, we have to decide whether we will, on this occasion, trust them. If we have no other reason to believe what they say, but trusting them will involve (perhaps inter alia) believing what they say, then we are deciding to believe.

Posted by Brian Weatherson at 12:36 am

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22 August, 2006

Terence Tao

Terence Tao, an Australian now working at UCLA, has won a Fields medal. I’m naturally very pleased to see an Australian Fields medallist. I also knew Prof Tao a little back when I was a high school maths student and he was a remarkable prodigy, having just become the youngest person to win a Maths Olympiad gold medal. I’ve always had this image, I think more from movies than anything else, that prodigies like that tend to burn out. Clearly he didn’t.

To give you a sense of how broad Tao’s work is, the work on prime numbers that was highlighted in the Fields citation is the seventh category heading on his preprints page. And he’s either editor or an editorial board member on four journals. Some days I think I need to work harder. In the meantime, congratulations to Professor Tao for some really remarkable accomplishments.

Posted by Brian Weatherson at 3:36 pm

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21 August, 2006

Philosophical Review Online

As many of you will know, Philosophical Review is moving to Duke University Press. What you might not know, what indeed I didn’t know until a few minutes ago, is that Duke has quite a nice webpage for the Review. If your institution subscribes to the Review, you should even be able to access recent issues (through April 2006) that are online. For many people that will mean that there are a lot of new Philosophical Review papers available for them to read!

UPDATE: Dave Chalmers pointed out to me that Duke is actually running a free trial of the Review website until September 27. So between now and then you can get any of the articles that you like. (And there are 20 or so articles that are posted that won’t have arrived by paper yet.) We might start some discussion threads on some of the papers here over that time.

Posted by Brian Weatherson at 2:21 pm

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11 August, 2006

Finks, Dispositions and Abilities

At the recent Bellingham conference, Ted Sider (in discussion of a paper by Kadri Vihvelin) made what I thought was a very good point about dispositions and conditionals. What follows are largely reflections on how Ted’s point affects debates about free will. I don’t think many of my conclusions here are original – what I say ends up being pretty close to what Neil Levy says in Frankfurt Finked (PDF), but perhaps the way I get there will be interestingly different. (And it is an excuse to display my Austinian tendencies in some detail.)

Consider the familiar example of the glass liked by a powerful sorcerer. The glass is a duplicate of my glass that will break if struck. But this glass won’t break if it is struck. The sorcerer will anticipate the strike and at that moment change the intrinsic structure of the glass so that it can handle being struck. Intuitively, the glass is still fragile, but it won’t break if it is struck. So the following identity is false.

Now here is Ted’s point. From the example we know that not both of the following identities can be true.

But the example alone doesn’t tell us which of the identities is false, just that one or the other is. Most of the recent literature on dispositions has focussed on the second identity as what is wrong. But once Ted raised it, it seemed to me that we should think again about the first identity. Read the rest of this entry »

Posted by Brian Weatherson at 1:46 pm

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Ellery Eells

Over at Crooked Timber, Harry Brighouse reports the sad news that his colleague Ellery Eells has died. As Harry says, Eells’ combination of technical ability and philosophical insight was rare and valuable. I never met him, but both Harry and Larry Shapiro report he was also a wonderful person and colleague as well.

UPDATE: In comments Branden Fitelson, who was a student of Eells, has some memories of what Eells was like as a teacher and supervisor.

Posted by Brian Weatherson at 12:35 pm

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10 August, 2006

Sorites Arguments in Mathematics

First of all, I’d like to thank Brian for inviting me to post here (like Gillian and Carrie, and some others that haven’t decided to say anything yet).

The topic I’m interested in is a parallel between the sorites arguments typical in discussions of vagueness and certain arguments for the adoption of strong new axioms in set theory. (I discussed some of those arguments in this post on my other blog.)

Basically, the idea is based on Gödel’s second incompleteness theorem. For every nice enough theory T (basically, T needs to be strong enough to represent basic arithmetic, and orderly enough that you can tell whether or not a given statement is an axiom), there is an arithmetical statement called Con(T) that says that T is consistent. However, for any such T, the statement Con(T) is neither provable nor disprovable from T itself. But if T has only true statements as axioms, then it must clearly be consistent, so T is incomplete. In particular, there is a true theory T’ that proves all the consequences of T, but also proves Con(T), and we should adopt T’ instead of T.

Because this argument then applies to T’ as well, we seem to either have to withhold judgement on our initial theory, or adopt a theory far stronger than what we started out with. (A recent post of mine discusses a parallel argument by Roger Penrose that claims to show that our mathematical knowledge is given instead by a non-computable theory.) Set theorists often use this argument to show that mathematicians who accept the axioms of ZFC (the standard framework most mathematicians tacitly accept as the foundations of what they do) must therefore accept much stronger principles as well, despite the fact that they can’t be proven.

I’d like to agree with the set theorists, but this argument reminds me of some fallacious reasoning in cases of vagueness. The idea is that for each theory T, if T is true, then T+Con(T) must be as well. This is similar to the claim that for every n, if n grains of sand don’t make a heap, then n+1 don’t either. The argument that shows mathematicians must accept every large cardinal claim that set theorists come up with is parallel to the argument that there are no heaps of sand. It seems plausible to me that whatever account of vagueness one has to block the heap argument could be adopted to block the set-theoretic argument. On the other hand, if a solution to the problem of vagueness doesn’t apply to the mathematical case (perhaps because it seems implausible to assign intermediate truth-values to mathematical claims or something), then one might see this solution as somehow lacking.

Some people might also run the sorites argument as a modus tollens instead of a modus ponens, saying that any number of grains of sand form a heap, and similarly that ZFC is not true (because adopting it as true forces them towards further claims about large sets that they have trouble believing).

A position like this is adopted by finitists, who accept claims about various finitary mathematical objects (like natural numbers, rational numbers, and the like) but only accept “potential infinities” (like a list that one can keep adding to) rather than “completed infinities” (like the actual precise value of some irrational number, or some non-computable set of natural numbers). However, most finitists accept Peano Arithmetic as a set of axioms, and a similar argument works starting with PA to drive one seemingly inexorably towards ZFC, and thus to the higher infinite.

The even more drastic solution accepted by some is known as ultrafinitism, on which one doubts even some “finite” numbers. In practice, these doubts arise about extremely large numbers, like a googolplex, which are believed to be larger than the number of subatomic particles in the entire universe. However, a similar sorites argument is going to cause trouble for the ultrafinitist – if the ultrafinitist accepts that the natural number n makes sense mathematically, then it would also seem that she should accept that the natural number n+1 does as well. (After all, one can just take the set of n things that one already has, and add this set itself as an element to create a new set!) If this is right, then once one accepts that even a single natural number makes sense, this successor principle pushes one inexorably towards at least full finitism, if not towards the infinite. The ultrafinitist has to reject the claim that every natural number has a successor, but it seems that she shouldn’t point to any number as “the last one”.

I’d like to use these arguments to show that once one adopts any amount of mathematics, one basically has to go “all the way to the top” in terms of the scales of infinity. However, these arguments seem to share troubling features with sorites arguments that we do want to block, so I’m interested in seeing what accounts of vagueness might do to them.

(The idea for this post originated in a class I co-taught last week with Mike Shulman to mathematically talented high school students at the Canada/USA Mathcamp.)

Posted by Kenny Easwaran at 6:10 pm

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Belief and Probability

In this paper, I offered the following analysis of belief.

S believes that p iff for any* A, B, S prefers A to B simpliciter iff S prefers A to B conditional on p.

The * on any is to note that the quantifier is restricted in all sorts of ways. One of the restrictions is senstive to S’s interests, so this becomes a version of interest-relative invariantism about belief. And if we assume that belief is required for knowledge we get (with some other not too controversial premises) interest-relative invariantism about knowledge.

I now think this wasn’t quite the right analysis. But I don’t (yet!) want to take back any of the claims about the restrictions on any. Rather, I think I made a mistake in forcing everything into the mold of preference. What I should have said was something like the following.

S believes that p iff for any* issue, S’s attitudes simpliciter and her attitudes conditional on p match.

Here are some issues, in the relevant sense of issue. (They may be the only kind, though I’m not quite ready to commit to that.)

Previously I’d tried to force the second issue into a question about preferences. But I couldn’t find a way to force in the third issue as well, so I decided to retreat and try framing everything in terms of issues.

Adding questions about probability to the list of issues allows me to solve a bunch of tricky problems. It is a widely acknowledged point that if we have purely probabilistic grounds for being confident that p, we do not take ourselves to (unconditionally) believe that p, or know that p. On the other hand, it hardly seems plausible that we have to assign p probability 1 before we can believe or know it. Here is how I’d slide between the issues.

If I come to be confident in p for purely probabilistic reasons (e.g. p is the proposition that a particular lottery ticket will lose, and I know the low probability that that ticket will win) then the issue of p’s probability is live. Since the probability of p conditional on p is 1, but the probability of p is not 1, I don’t believe that p. More generally, when the probability of p is a salient issue to me, I only believe p if I assign p probability 1.

However, when p’s probability is not a live issue, I can believe that p is true even though I (tacitly) know that its probability is less than 1. That’s how I can know where my car is, even though there is some non-zero probability that it has been stolen/turned into a statue of Pegasus by weird quantum effects. Similarly I can know that the addicted gambler when end up impoverished, though if pushed I would also confess to knowing there is some (vanishingly small) chance of his winning it big.

Posted by Brian Weatherson at 4:41 pm

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Patrick Kain on Kant’s Second Critique

Realism and Anti-Realism in Kant’s Second Critique by Patrick Kain.

This article surveys recent work on Kant’s Critique of Practical Reason, with a particular focus on his doctrine of the fact of reason and his doctrine of the practical postulates, assessing the implications of such work for the debate about realism and antirealism in Kant’s moral philosophy. Section 1 briefly surveys some salient considerations raised by Kant’s first Critique and Groundwork. In section 2, I survey recent work on the Kant’s doctrine of the fact of reason and argue that it does not support an anti-realist interpretation of Kant’s ethics. In section 3, I argue that recent work on Kant’s doctrine of the practical postulates does not support an anti-realist interpretation of Kant’s ethics.

Posted by Brian Weatherson at 12:07 pm

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Iris Marion Young

Soon after I left last week, I heard the news that Iris Young had died. I didn’t know her at all, so I don’t have anything to add to the heartfelt reminisces of those who did. There are hundreds of blog posts on her listed here. The Chicago memorial notice is here. Daniel Drezner was a colleague of hers at Chicago.

It would be safe to say that Iris and I disagreed a fair amount on matters of politics and policy. It would also be safe to say that I really did not care. Iris was one of the more decent people I’ve met in the academy — indefatigable and interested in everything. Her students — and there were many of them — were devoted to her.

She had been suffering from cancer for the past year or so, not that this slowed her down all that much. The way she carried herself was remarkable — not because Iris was all bulldog determination in the face of her illness and treatment, or any such maudlin sentiment. Rather, she was cheerfully unafraid to tell you exactly how she was feeling, and doing so in a way that filtered the awkwardness out of the conversation.

She was both brave and gentle, and she will be missed.

Posted by Brian Weatherson at 11:38 am

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3 August, 2006

Two Paths to Glory

Cordelia Fine has an article in the Australian about the thesis that self-control is the key to academic success. The article presents a way of thinking – supported by a study involving chocolate chip cookies and radishes – according to which self-control is like a muscle: it gets tired.

Moreover the “muscle” that you use to read tedious articles, write 500 words a day and refrain from telling your advisor/students what you think of them is the same muscle that helps you go for a run and reject chocolate chip cookies. (This, I suspect, explains the Princeton grad student phenomenon known as “Generals Belly”.)

Fine discusses two ways to maximise self-control for your work – both suggested by the muscle analogy. The first is to build up your self control – by exercising it. But fortunately her philosopher father has developed another way:

My father, a professional philosopher, has a job that involves thinking very hard about very difficult things. This, of course, is an activity that consumes mental resources at a terrific rate.

The secret of his success as an academic, I am now convinced, is to ensure that none of his precious brainpower is wasted on other, less important matters. He feels the urge to sample a delicious luxury chocolate? He pops one in his mouth. Pulling on yesterday’s shirt less trouble than finding a clean one? Over his head the stale garment goes. Rather fancies sitting in a comfy armchair instead of taking a brisk jog around the park? Comfy armchair it is. Thanks to its five-star treatment, my father’s willpower – rested and restored whenever possible – can take on the search for wisdom with the strength of 10 men.

Ah, it’s good to know that top philosophers are still at the forefront of psychological research.

Apparently Cordelia Fine works for Centre for Applied Philosophy Public Ethics here at the University of Melbourne (where I’m spending the summer). Maybe I can persuade her to come to Brunetti’s with me…

Posted by Gillian Russell at 3:50 am

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