Donald Davidson

Brian Leiter reports the very sad news that Donald Davidson has died. As Chris Bertram noted the last few years have seen a horrible number of philosophical greats die. (Chris mentions that Lewis, Nozick, Rawls and Williams died within the last two years, and Quine died just over 2 years ago.)

Both Chris and Brian are collecting tributes and obituaries at their sites as they come in, so check back there for links to those tributes.


Just for fun, here’s the conclusion from Michael Ruse’s entry on Creationism in the Stanford Encyclopaedia of Philosophy.

Creationism in the sense used in this discussion is still very much a live phenomenon in American culture today and in other parts of the world, like the Canadian West, to which it has been exported. Popularity does not imply truth. Scientifically Creationism is worthless, philosophically it is confused, and theologically it is blinkered beyond repair. But do not underestimate its social and political power. As we enter the new millennium, thanks to Johnson and his fellows, there are ongoing pressures to introduce non-evolutionary ideas into science curricula, especially into the science curricula of publically funded schools in the United States of America. And things could get a lot worse before they get better, if indeed they will get better. Already, there are members of the United States Supreme Court who have made it clear that they would receive sympathetically calls to push evolution from a preeminent place in science teaching. If future appointments include more justices with like inclinations, we could find that nearly a century after the Scopes Trial, when the Fundamentalists were perceived as figures of fun Creationism finally takes its place in the classroom. If this essay persuades even one person to take up the fight against so awful an outcome, then it will have served its purpose.

The point that Creationsm is a distinctive American phenomenon (some minor infections in Canada notwithstanding) seems worth remembering. As far as I can tell, Creationism is a really unpopular view even among theists in Australia, and my impression is that this is also true in most of western Europe. It might be fun to spend the afternoon making up pop-sociology explanations for this difference, but I fear some real sociologists might make fun of me if I did that.

Probability and Emotions

It’s well known that our intuitive approaches to probabilistic reasoning lead to fairly bizarre beliefs and behaviour in some circumstances. It can also lead to fairly odd attitudes and emotions in the right circumstances. Consider, for example, how it would feel being a fan of the various teams in the American League playoff race.

Baseball Prospectus has introduced a new model calculating the probability of each team reaching the playoffs given their current standings, their performance to date, and their upcoming schedule. I don’t know how good the model is, but let’s assume for now it’s accurate. If so, here’s the probability of each team making the playoffs as of the morning of August 30.

Yankees 91.5%
As 80.0%
Red Sox 73.0%
Mariners 51.7%
White Sox 46.2%
Twins 38.5%
Royals 18.1%

From that report you’d think Mariners fans should be at least as happy about their position as White Sox fans, maybe more so. But I suspect that’s not the case right now, because of the odd way the playoff teams are chosen.

There’s four playoff teams – the winners of the eastern, central and western divisions, and a wildcard for the best second place team. In effect the best three of the Yankees, As, Red Sox and Mariners will go through, two as eastern and western winners and the third as wildcard. And the best of the White Sox, Twins and Royals will go through as winner of the central.

Right now in the four team race for three spots, the Mariners are looking by far the weakest of the four. It’s pretty close, but it’s much easier to see the Mariners missing than any of the other three. It would be hard to feel particularly happy about your position if you’re a Mariners fan, because one of the four has to miss and you’re the most likely one to do so, by far.

The three team race for the central crown is tighter, but the White Sox have the upper hand right now. It would be easy to feel confident if you’re a White Sox fan. One of the three teams has to go through, and it’s most likely going to be you.

It should be clear what went wrong in the reasoning in the last sentence of each of the last two paragraphs. When there are many possible outcomes, you shouldn’t pay as much attention to which of them is most likely as much as to how probable each of them is. If Mariners fans did that they would think “I don’t know who we’re going to finish ahead of, but I’m still confident enough we’ll finish ahead of someone.” And if White Sox fans did that they might think “I don’t know who’s going to beat us, but it’s still a good chance that someone will beat us.” (That might be too depressing – it’s better if you’re a fan to focus on the positive sometimes. It’s possible to be too rational in sports sometimes. So let’s focus on why Mariners fans might be too depressed.)

The fallacy here, assigning too much weight to the most likely outcome, is I think reasonably common. But even once you’ve seen it it’s hard to overcome it. If I were a Mariners fan, I’m not sure I’d find the reassuring speech in the last paragraph that reassuring, even if I could (at some level) recognise the soundness of the reasoning.

Trolley Problems

Here’s a new-sounding version of the trolley problem due to Carolina Sartorio posted on Philosophy from the (617).

Fatman*: There are five people tied up to a track. One of them is a fat man, and somehow I can shove him into the path of the train (although I can’t save him!) to stop the train before it kills the other four.

There’s two puzzles here. The first, in which Carolina is interested, is whether the action is permissible in this case. The second, which seems more fun to me, is whether we can tell anything like a plausible story in which the facts are as Carolina stipulates. I’m moderately dubious that this can be done, but I should never underestimate the powers of storytellers.

I wonder if the intuitions about the cases will differ depending on just how the details are set out. Just for fun, here’s a variant that I think is like the basic switch-tracks-killing-one-to-save-five-case.

Evil Demon: An evil demon has set up a run away steam engine to travel through five tunnels, killing the people tied to the tracks in each tunnel. You can’t stop the train (it’s got a really powerful engine) but you can change the order in which the train goes through various tunnels. You notice that the man tied to the tracks in tunnel #5 (i.e. the tunnel the train is scheduled to go through fifth) is really fat. It looks probable the train will derail when it hits him. (It’s a pretty resilient train, so it can run over the supermodels in the other four tunnels without being derailed, but it can’t handle the fat man. Probably.) So you reroute the train to go through his tunnel first, it hits him, kills him and is derailed, saving the four.

Is this action permissible? Is it mandatory? Is it a sign of completely awful character that one even thinks about these puzzles? Of worse character to write about them? Of even worse character to write about them on two blogs?

(By the way, I think Philosophy from the (617) needs a name change. By my count currently 3 of the 14 listed philosophers are actually in the 617 area code. There’s a sense in which they are all connected to it, but then there’s a sense in which anyone with a phone line is connected to the 617 area code too.)


I wrote up my blog post from a couple of days ago about evidence and knowledge into a short paper. I thought the APA deadline was today so I sent it off in remarkably unpolished form, but it turns out the deadline isn’t until next Tuesday. It could have been a pretty good paper by then I guess, but alas not to be.

Time Travel Movies

(This was originally published on Crooked Timber.)

I’m teaching a freshman seminar on time travel at Brown this year, so I’ve been watching a lot of time travel movies as ‘preparation’. I always knew that many time travel movies don’t make a lot of sense on a bit of reflection. What surprised me on recent re-watchings was that some seemed unintelligible even on relatively generous assumptions.

Continue reading “Time Travel Movies”

What I Did With My Semester (pre-semester draft)

Here’s what I’m doing this semester. (Or at least what I predict I’m doing – we may have to check back in four months to see whether my predictions are mostly correct.) It looks kind of busy at first, but I think (a) it’s a lot less work than most people in the real world have to do, and (b) I can’t imagine it will slow down blogging perceptably, except at the times I’m at these events. (Or in some cases travelling to them.)


  • Mathematical Logic: Tuesday and Thursday 9-10.30
  • Time Travel: Tuesday and Thursday 10.30-12

I’m also teaching a continuing ed version of the time travel course for six weeks on Wednesday nights starting late September. (Why? Don’t know. It must have seemed like a good idea once upon a time.)


  • Kit Fine’s course on abstract objects at Harvard Tuesday 4-6. (Probably attending at this stage.)
  • The semantics reading group in the linguistics dept here, although I don’t know the time for that.

From time to time I guess I’ll sit in on some of the other seminars, especially Jamie Dreier’s course on moral realism Friday afternoons. It looks like that course will be fairly atomistic, so I can jump in from class to class.


  • At Brown: Frank Arntzenius (Sept 15), Tim Crane (Sept 22), Anil Gupta (Oct 20), John Broome (Oct 27, 29, and 30), Ken Walton (Nov 10), Ruth Milikan (Nov 17).
  • At MIT: Michael Smith (Sept 19), Karen Bennett (Oct 3), Keith DeRose (Oct 31), George Bealer (Nov 14), Jason Stanley (Dec 5). (MIT also has some overlap with our colloquium schedule, but I don’t think I’m so much of a philosophy junkie to see the same person at two different depts in two days. Though I did that once last year I guess.)

For various reasons I’ve never got into the habit of going to Harvard colloquia. Unless they update their schedule I guess that won’t change this year.

Depending on finances, time, etc., some combination of:

If anyone is driving to any of these from Providence and wants a passenger, let me know. If you know of other conferences that will be fun, especially if they are within driving distance of Providence, really let me know!

Well who knows in between all that, but I need to (co-)write a paper on epistemic modals very soon, do the final drafts of my papers on truer and on luminosity, and I’d like to finish up the imaginative resistance paper, try writing something semi-informed about the use of the modularity of mind hypothesis in epistemology and do the modal parts/temporal parts comparison that I mentioned this morning.

I also need to write something on applied ethics for the (wonderful) International Symposium on Theoretical and Applied Ethics at Baton Rouge. (Note the link is to last year’s program. I couldn’t find a website for this year’s event yet.) And in the medium term I have to write something on intuitions, methodology and zombies that I promised to a conference. But that’s not for a while yet I think.

Time Travel

In the first 40 mins of the philosophy dept ‘Open House’ I’ve already got a wait list of 8 people for the time travel course (which is currently full at 20). If this is indicative of its popularity I might have made a mistake making this a seminar course rather than a big lecture course.

UPDATE: The pace has dropped off a little, but we’re now (Fri 12.30) at a waiting list of 13. At this rate by the time the class starts we’ll have more on the wait list than in the class.

Modal Parts

I don’t think I have a lot of way-outside-the-mainstream philosophical beliefs; in fact I think I have considerably fewer of them than I’d like. Probably the most extreme of my positions is that I believe in modal parts.

The idea behind the doctrine of modal parts is that for any object o and class of worlds W such that o exists in every member of W, o has a part o’ that exists in every world in W and in no world outside of it. (The obvious analogy is to temporal parts. This analogy will get pressed a lot as we continue.) This isn’t quite a strong enough position, because this makes it sound as if actualism implies modal parts, and modal parts is meant to be a much more outrageous position. The trick, as with getting temporal parts and presentism to sing in harmony, is to restate the doctrine using operators, or something like them. Here’s what I take the position to be.

For any class of worlds W, let pW be a proposition that is true at all and only the worlds in W. The doctrine is that for any object o and class of worlds W such that Necessarily, if pW then o exists, o has a part o’ such that Necessarily, o’ exists iff pW.

If modal realism is true, this is equivalent to the earlier statement of the doctrine of modal parts. However, even if modal realism is not true, this doctrine makes a striking claim about the existence of objects that are ‘world-bound’ relative to whatever our actualist takes worlds to be.

Given that I hold such a view, one might wonder what my arguments for it are. I was wondering just that this morning, and it seemed the arguments for it probably aren’t as bad as orthodoxy would have you think, but probably aren’t as good as I’d like.

The motivation for believing in modal parts is a generalised suspicion of extended simples. But suspicion is not an argument.

One real argument would be the problem of contingent intrinsics. In Plurality that’s Lewis’s main argument for (something like) the doctrine of modal parts. Stephen Yablo has argued that this argument won’t extend to objects that don’t vary in intrinsic property between worlds in W. In general I’ve never been strongly moved by arguments for parthood from intrinsicness, so I don’t want to rest too much weight on this.

Other arguments come from analogy with arguments for temporal parts. Since Ted Sider has collected so many of those in Four-Dimensionalism, I should just try stealing the best. (Ah, the advantages of theft over honest toil.)

One nice use for modal parts, I think probably the best use, is in resolving some of the paradoxes about coincidence and constitution. I think the modal partser has by far the best story to tell here. On the one hand, she can say that the statue and the lump are distinct fusions of modal parts, and hence respect the argument from Leibniz’s Law that they are not identical. On the other, she can say that there’s a good sense in which there is only one object here, because they both exist in virtue of having a common modal part. I’ve never seen another story about the paradoxes that gets nearly as close to capturing ordinary intuitions as the modal parts story.

Ted’s main argument for temporal parts, the argument from vagueness, also extends across. (The following sketch is incomplete at every step. I’ll try one day to write it up properly and see how the arguments carry across.) Assume that the doctrine of modal parts is not generally true. Still, it seems that for some o, W there will be an o’ such that Necessarily, o’ exists iff pW. Any principle about when such an o’ exists (other than the no parts claim that o’ exists iff o’=o and W is the class of worlds at which o exists) will be vague. But that will imply that it is vague how many things there are, which is intolerable. So we should be ‘universalists’ about modal parts – for any o and W in which o exists, o has a part o’ in W only.

One class of arguments for temporal parts, however, does not carry across: the arguments from time travel. I assume that genuine travel between worlds is a conceptual impossibility, even for a modal realist. So we can’t argue that the possibility of modal travel requires modal parts, and modal travel is possible, so modal parts exist, because premise 2 is false. This is a disanalogy with the argument for temporal parts, and perhaps a fatal one.

I suspect the vagueness argument will turn out to have holes in it when the details are spelled out. I worry that the nihilist position may turn out to be quite plausible. And I worry that there will be no way to argue from the vagueness of an intermediate view to any vagueness in how many things there are. So the arguments from constitution may have to do all the work. I think they probably can, but it’s not the strongest foundation for a metaphysical theory.

Mixed Modals

While looking around Amazon for time travel movies, I found the following remarkable construction in a review of Bill and Ted’s Excellent Adventure. (The context is a long list of complaints about the DVD not including anything except the movie, and not including, for example, deleted scenes.)

there have to possibly be deleted historical figures

Well, anything’s possible I suppose.