• Thought, Vol 1, Issue 1, March 2012

I was wondering whether it would be good to have comments threads on different papers in it. If anyone is interested, let me know and I’ll set them up.

One is that the In Our Time archives have now been made available. This is a very nice thing for the BBC to do, and I suspect I’ll be spending a lot of time listening to them over the forthcoming months.

The other is that there is a lot of demand out there for philosophy podcasting. As well as In Our Time (which has over 60 philosophy programs in its archive), there were a lot of recommendations for David Edmonds and Nigel Warburton’s Philosophy Bites.

So in the interest of satisfying that demand, I thought I’d post a link to a couple more philosophy podcasts, and see if TAR readers had suggestions for more.

Philosopher’s Zone is a weekly philosophy show on Australia’s Radio National. It features a mixture of public lectures, interviews with philosophers, and programs on specific topics.

The 10-Minute Puzzle is a new podcast series out of the Northern Institute of Philosophy centre in Aberdeen. It basically does what it says on the tin: introduce a philosophy puzzle and some of the natural solutions to it in 10 minutes.

The links I’ve posted so far have a pretty high concentration of male presenters. But I’m sure that if I knew more about what was available, that imbalance would be somewhat corrected. So, any further suggestions?

Even people who appear, to naive judges, to be fluent in a second language they learned after childhood, perform well below native speakers at cognitively demanding linguistic tasks, such as understanding speech in noisy environments, or explaining proverbs. I don’t have the citation link for this, but Jürgen Meisel reported that German students learning French by immersion did much better if the immersion started between 32 and 42 months than they did if they started after 42 months. The errors that he reported were common among the older learners after several months of immersion, like not getting the genders of articles right even for words like maman where you would think it was obvious, were really striking. Karen Emmorey reported that the same thing was true for learners of ASL; late learners can become fluent enough for practical purposes, but are never as good as people who learn ASL in early childhood.

The striking contrast to all this is how successful first language acquisition is. To a first approximation, 100% of people successfully learn the syntax of their first language, and do so at a staggeringly young age.

I realised a few days after the symposium that there was a huge question I wish I’d asked. Why are we so good at learning a first language, and so poor at learning a second language. What cognitive system would have such a feature(/bug), and what evolutionary advantage could there be to having such a system?

Here’s one possible answer that I think is simple, explanatory, and sadly not consistent with the data. As Gilbert Harman noted in his talk, philosophers have long argued about the question of whether humans think in language. (Being philosophers, they’ve also argued about what the question even means, and that’s not a trivial issue.) Let’s adopt the following working hypothesis: humans who have learned a first language think in it, those who haven’t, don’t. This transition, from not thinking in language to thinking in it, runs very deep in the system. Once you have learned a language, it is impossible to not think in it. Compare the striking fact that once you learn a language, it is impossible to not interpret sounds you hear that are communications in that language. Once this transition is made, learning a language goes from being an instinctive task to a cognitive task. In Kahneman’s terms, it goes from being a system 1 task to a system 2 task. And learning a language is just too hard a task for system 2; it is literally harder than rocket science or brain surgery.

This obviously can’t be the complete story; a full explanation would need to fill in a lot of gaps. And the analogy I appeal to with Kahneman’s system 1/system 2 can’t be completely right. In Kahneman’s examples, system 2 is supposed to be more accurate than system 1, but self-consciously learning a language ends up being less accurate. The bigger problem, however, is that the hypothesis gets the timing all wrong.

The Meisel studies I mentioned do say that learning a language gets harder after about 42 months. They don’t say it gets harder after 24 months, let alone after 36 months. In fact, the students who start second language immersion then seem to do pretty well. But my little hypothesis would predict they’ll do badly, since by those ages they do speak their first language.

There’s also a problem at the other end. Profoundly deaf children with hearing parents often don’t learn a sign language until very late. And since they are deaf, they don’t learn a spoken language either. But that doesn’t mean their minds retain the plasticity to adopt a new language as a native speaker. Instead (at least according to results Karen Emmorey mentioned in Q&A), they do worse than even second language learners of ASL.

So I don’t have much of a theory as to why we should be wired this way. I assume that something in the ballpark of my hypothesis is right. Our ability to learn language isn’t switched off, it is inhibited by some other abilities we acquire. But how that inhibition works, I don’t really know.

It’s possible of course that there is a widely known and well supported explanation for this phenomenon. If so, I’ll be a little disappointed that it didn’t come up last week. But I rather doubt it does exist. One of the themes of the talks was that there was much less research on bilingualism than you’d expect, given how big a feature of the world it is. And most of the relevant data being discussed seemed to be from very recent studies. So I think until recently we didn’t know many of the facts to be explained, let alone have an explanation of them. Still, this is not at all an area I’m an expert in, and I’m sure many TAR readers will be able to point to more informed speculation than mine.

The talks at the Weinberg Symposium were videotaped, and I believe they’ll be posted to the web shortly. I’ll update this post when that happens.

Thanks again to Marshall Weinberg for sponsoring this event. Marshall sponsors many, many things at the University of Michigan (including my job!), and the intellectual environment here is much richer for it.

• The Role of Naturalness in David Lewis’s Theory of Meaning.
• Induction and Supposition.
• The Temporal Generality Problem. (This supersedes A reductio for reliabilism.)

There are also a couple of summer courses I’ve been asked to announce.

Problems of the Self at CEU.

The course aims to present the state of the art in research on the self from philosophy, psychology, cognitive neuroscience, sociology, and cognitive anthropology. Themes revolve around the nature of the self, as revealed through self-consciousness, body perception, action and joint action, and its embedding in society and culture. Historical and developmental perspectives provide other angles on the self. The course presents a unique opportunity for interdisciplinary discussion on the self from multiple perspectives. It is directed at advanced graduate students, postdoctoral fellows and junior faculty working in philosophy, psychology, cognitive neuroscience and cognate disciplines.

Metaphysical Mayhem at Rutgers.

Metaphysical Mayhem is back! Rutgers University will be hosting a 5-day summer school for graduate students May 14-18, 2012. John Hawthorne, Katherine Hawley, Ted Sider, Jonathan Schaffer, and Dean Zimmerman will lead the seminars on a variety of topics in metaphysics, including: natural properties, composition as identity, grounding, metaphysical explanation, and stuff like that…

The problem of the many diverse actual causal mechanisms, or more generally of many diverse mechanisms coexisting in any one world, is still with us. If causation is, one might be, wildly disjunctive, we need to know what unifies the disjunction. For one thing the thug platitudes tell us is that causation is one thing, common to the many causal mechanisms. (76)

But in Void and Object, Willis says that the Canberra plan approach is a good approach to determining what biff is, and he makes the following speculations about what kind of thing biff will turn out to be.

Myself, I’d like to think that the actual occupant of the biff-role is Humean-supervenient, physical, and at least fairly natural; but nothing else I shall say here is premised on that hope. (284)

Here’s the problem. There are, as Lewis says in Causation as Influence, many actually existing causal mechanisms. They don’t seem to have a lot in common. So biff looks like it should be pretty disjunctive. Yet Lewis says, or at least hopes, but it will turn out to be fairly natural. I don’t see how both those things can be true.

Essays should generally be no longer than 10,000 words; longer essays may be considered, but authors must seek prior approval. To be eligible for the 2012 prize, submissions must be electronically submitted by 30 January 2012 (paper submissions are no longer accepted). Refereeing will be blind; authors should omit remarks and references that might disclose their identities. Receipt of submissions will be acknowledged by e-mail. The winner is determined by a committee of members of the editorial board of Oxford Studies in Metaphysics, and will be announced in early March. At the author’s request, the board will simultaneously consider entries in the prize competition as submissions for Oxford Studies in Metaphysics, independently of the prize.

Previous winners of the Younger Scholar Prize are:

• Thomas Hofweber, “Inexpressible Properties and Propositions”, Vol. 2;
• Matthew McGrath, “Four-Dimensionalism and the Puzzles of Coincidence”, Vol. 3;
• Cody Gilmore, “Time Travel, Coinciding Objects, and Persistence”, Vol. 3;
• Stephan Leuenberger, “Ceteris Absentibus Physicalism”, Vol. 4;
• Jeffrey Sanford Russell, “The Structure of Gunk: Adventures in the Ontology of Space”, Vol. 4;
• Bradford Skow, “Extrinsic Temporal Metrics”, Vol. 5;
• Jason Turner, “Ontological Nihilism”, Vol. 6;
• Rachael Briggs and Graeme A. Forbes, “The Real Truth About the Unreal Future”, Vol. 7;
• Shamik Dasgupta, “Absolutism vs Comparativism about Quantities”, forthcoming, Vol. 8.

Enquiries should be addressed to Dean Zimmerman.

Now to be sure some of this could be due to philosophers who were born in 1960 having not yet produced their best work – lots of great philosophical work is published after one’s 51st birthday. And it could be because those philosophers have produced great work that hasn’t yet dissipated widely enough to be cited.

But I don’t believe either explanation. For one thing, Eric notes that if anything, the boomers are at the age where philosophers’ influence typically peaks. For another, the stats Eric posts back up something I’ve heard talked about in conversation a bit independently.

There are lots of very prominent, and ground-breaking, philosophers in my generation. (I’m defining generations in a way that my generation includes roughly people born between 1965 and 1980.) And looking at the current crops of grad students, the next generation looks fairly spectacular too. But between the generation of Lewis, Kripke, Fodor, Jackson etc, and my generation, there aren’t as many prominent, field-defining figures. It’s not like there are none; Timothy Williamson alone would refute that claim. But I didn’t think there were as many, and neither did a number of people I’ve talked about this with over the years, and Eric’s figures go some way to confirming that impression.

Eric also makes a suggestion about why this strange state of affairs – strange because you’d expect boomers to be overrepresented in any category like this – may have come about.

College enrollment grew explosively in the 1960s and then flattened out. The pre-baby-boomers were hired in large numbers in the 1960s to teach the baby boomers. The pre-baby boomers rose quickly to prominence in the 1960s and 1970s and set the agenda for philosophy during that period. Through the 1980s and into the 1990s, the pre-baby-boomers remained dominant. During the 1980s, when the baby boomers should have been exploding onto the philosophical scene, they instead struggled to find faculty positions, journal space, and professional attention in a field still dominated by the depression-era and World War II babies.

That’s an interesting hypothesis, though it seems that if it is true, it should generalise to other disciplines. And I’m wondering whether it does. Are baby boomers underrepresented among the leading figures in other fields such as political science, history, sociology, English literature and so on? If not, I think we need another explanation for philosophy’s recent history.

• A decision problem is a triple (S, A, U) consisting of a set of states, a set of actions, and a utility function that maps state-action pairs to utilities.
• An agent faces a decision problem (S, A, U) if she knows that her utility function agrees with U about how much she values each state-action pair, she knows she is able to perform each of the actions in A, and she knows that exactly one of the states in S obtains.
• A decision problem (S’, A, U’) is an expansion of a problem (S, A, U) for agent x iff S’ is a superset of x, U’ agrees with U on every state-action pair where the state is in S, and the agent knows that none of the states in S’ but not S obtain.

Then I have endorsed the following principle:

Ignore Known Falsehoods. If (S’, A, U’) is an expansion for x of (S, A, U), then the rational evaluability of performing any action φ is the same whether φ is performed when x faces (S’, A, U’) or when she faces (S, A, U).

I’m now worried about the following possible counterexample. Let’s start with two games.

Game One. There are two players: P1 and P2. It is common knowledge that each is rational. Each player has a green card and a red card. Their only move in the game is to play one of these cards. If at least one player plays green, they each get $1. If they both play red, they both get $0. P2 has already moved, and played green.

Game Two. There are two players: P1 and P2. It is common knowledge that each is rational. Each player has a green card and a red card. Their only move in the game is to play one of these cards. If at least one player plays green, they each get $1. If they both play red, they both get $0. The moves will be made simultaneously.

Here’s the problem for Ignore Known Falsehoods. The following premises all seem true (at least to me).

1. Games are decision problems, with the possible moves of the other player as states.
2. In Game One, it doesn’t matter what P1 does, so it is rationally permissible to play red.
3. In Game Two, playing green is the only rationally permissible play.
4. If premises 1 and 3 are true, then Game Two is an expansion of Game One.

The point behind premise 4 is that if rationality requires playing green in Game Two, and P2 is rational, we know that she’ll play green. So although in Game Two there is in some sense one extra state, namely the state where P2 plays Red, it is a state we know not to obtain. So Game Two is simply an expansion of Game One.

So the big issue, I think, is premise 3. Is it true? It certainly seems true to me. If we think that rationality requires even one round of eliminating weakly dominated strategies, then it is true. Moreover, it isn’t obvious how we can coherently believe it to be false. If it is false, then rational P2 might play red. Unless we have some reason to give that possibility 0 probability, it follows that playing green maximises expected utility.

(There is actually a problem here for fans of traditional expected utility theory. If you say that playing green is uniquely rational for each player, you have to say that two outcomes that have the same expected utility differ in normative status. If you say that both options are permissible, then you need some reason to say they have the same expected utility, and I don’t know what that could be. I think the best solution here is to adopt some kind of lexicographic utility theory, as Stalnaker has argued is needed for cases like this. But that’s not relevant to the problem I’m concerned with.)

So I don’t know which of these premises I can abandon. And I don’t know how to square them with Ignore Known Falsehoods. So I’m worried that Ignore Known Falsehoods is false. Can anyone talk me out of this?

On that page, I’ve posted the notes I’ll be using for my decision theory class this fall.

• Philosophy 424 – Logic of Decision Notes

These notes are something of a merger of the game theory notes I used over the summer, with the decision theory notes I had previously posted. A straight merger of those two would have involved a lot of overlap, and been too long for a semester. As it is, these notes are probably a little long for a semester course, but I think that with careful use they should be the basis for a good course.