7/02/2007

Off to Africa, and 2nd birthday

This blog turns two years old today. I'm only averaging about two and a half posts per month, and certainly fewer than that this year. I'm finding myself spending more time on polishing up articles (and a book), and less on writing about brand-new, half-baked ideas better suited for a blog dedicated to obscurity and confusion.

Posting will be even lighter over the next 7 weeks or so, since my wife and I are headed to Zambia under the auspices of a couple of non-profits that she works with: FORGE, which works in refugee camps, and Project Educate, which aims to improve educational, medical, and other infrastructure in western Zambia. We're looking forward to the trip with a lot of anticipation, but a bit of trepidation too, since neither of us have ever been to Africa.

And many, many thanks to the folks who have provided feedback on the book manuscript. I am in your debt. If anyone wants a copy WITH the archival material appendix, please email me. I can't put it on the web, because the Archive from which it comes maintains control over it. This updated version also was my first sustained undertaking with LaTeX, so there are still typographic kinks in it.

5/10/2007

Help me write a book

This post falls under the category of "shameless begging." I am in the later stages of writing a book (based on my dissertation) called Carnap, Quine, and Tarski's Year Together. The plan is to send the manuscript to the publisher in about two months, i.e. very early July. Between then and now, the only thing I'm working on is the book.

I need your help with this. I would greatly appreciate any feedback, large or small, on the manuscript. It definitely needs to be looked at by a fresh set of eyes (preferably attached to a clever mind, but I'll take what I can get). The manuscript can be downloaded, as a 1MB Word file, here.

Thanks in advance to anyone who lends a hand. In my limited experience, the greater the number of people who tear apart something I've written, the better the final product is.

4/19/2007

Can a sentence without a truth-value ever be approximately true?

I am curious to hear people's thoughts on the question in the title. There has been a lot of philosophical work done on the idea that a sentence can be strictly speaking false, yet nonetheless approximately true (or 'truthlike' or 'verisimilar'). For example: I am 5'11", but if someone said 'Greg is 6 feet tall,' we want to say that that claim is approximately true or something like that. But what if the claim was (strictly speaking) neither true nor false? (Readers may insert their own favorite truth-valueless sentence here.)

I ask because, as I mentioned in an earlier post, I'm toying with the idea that the Pessimistic Induction over the history of science plus something like Kuhnian incommensurability (esp. untranslatability) will lead us not to the conclusion that current science is likely to be false, but rather is likely to lack a truth-value. For if we cannot translate the claims of a pre-revolutionary language into the post-revolutionary one, then the pre-revolutionary language (from our current point of view) is truth-valueless, not false.

I ask the question in the title because one common realist response to the Pessimistic induction is: "Well, yes, our current scientific theories are probably not exactly true, but they are approximately true." If truth-valueless sentences cannot be approximately true, then this response is not available to the realist.

4/13/2007

APA wrap-up: Kyle Stanford's "New Induction"

My time at the APA last weekend was pretty good: I learned a few new things, met some new people I've been wanting to meet, and got to catch up with a couple old friends. Particularly helpful/ enlightening presentations included Angela Potochnick on how the context of inquiry shapes explanation, Ken Waters (plus commenters Jay Odenbaugh and Michael Strevens) on causes that make a difference (not, I learned, to be confused with the conception of causes as 'difference-makers'), and the Author-Meets-Critics session on Kyle Stanford's Exceeding Our Grasp.

Stanford's basic claim is that current scientific theories are underdetermined -- not because we can generate empircially equivalent rivals to our currently accepted theories, but rather because at many, many times in the past, the scientific community has been unable to conceive of good alternatives to the then-current theory. The evidence that such alternatives exist is the fact that they are proposed and accepted centuries later: thus, Newton's mechanics did not consider special relativity as an alternative hypothesis; Newton's, when he proposed his gravitation theory, did not consider the general theory of relativity as an alternative; no classical physicists before 1900 considered quantum mechanics as an alternative explanation of the data, and so on. This is what Stanford calls the "New Induction" over the history of science.

The idea, as just presented, strikes me as a promising line to take. But there is one aspect of Stanford's presentation of the problem that I don't understand. Fiona Cowie asked (in part) about this in the question and answer session, but I still didn't follow the answer. Stanford says that (e.g.) in 1700, the special theory of relativity and Newtonian mechanics were "(roughly) equally well-confirmed". Similarly for the other cases: the future theory is supposedly just as confirmed as the old one -- even in the past.

I don't understand why Stanford says this for two reasons: (1) He doesn't need the theories to be equally well-confirmed for his point to hold (viz., scientists aren't even conceiving of a hypothesis that will later be accepted as superior), and (2) it seems false to me, on any reasonable (i.e., not hardcore hypothetico-deductive)notion of confirmation. In 1700, it is true that special relativity and Newtonian mechanics agreed on all the consequences that could then be observed. But someone who, in 1700, said "Newton is approximately right, yet when something goes really, really fast its length will contract and its local time will dilate from the point of view of slower-moving observers" -- there is NO evidence at all for postulating that further bit of theory. And it's the same with GTR (what evidence would there've been for gravitation being a 10-component tensor instead of a scalar?) and especially QM (what evidence was there for thinking a body cannot have a determinate position and momentum simultaneously?). In 1700, these now-accepted alternatives were consistent with the data, but they were not equally well-confirmed.

Note: a very similar line of objection is pushed at the end of P.D. Magnus's "What's New about the New Induction?" (Synthese, 2006), though he develops it slightly differently, I think. (As I understand him, P.D. claims that in 1700, STR, GTR and QM would look like 'gruesome' hypotheses.)

4/03/2007

Off to the Pacfic APA

I'll be at the APA in San Francisco from this Wednesday til Saturday afternoon; I'm be commenting on a paper by Barry Ward on the paradox of confirmation (a.k.a. the Ravens paradox).

So if you're there, and you want to catch up/ chat/ harrass me etc., please track me down.

4/02/2007

semantic pathology spotted in the wild

Perhaps the most famous instance of a sentence that exhibits semantic pathology is the Liar: 'This sentence is false'; if the 'this' strikes you as problematic --

(1) (1) is false.

But there are many other types of semantic pathology, such as the 'heterological' paradox and the so-called 'truth-teller': 'This sentence is true.' My colleague James Woodbridge is doing a lot of interesting research in this area; check out his work if you are interested.

This is not a serious post about semantic pathology, but rather just a field report. I sometimes wonder whether these examples like the truth-teller are all that important, since it's hard to imagine circumstances under which speakers might utter it. But I think I may have found a couple of instances of something akin to the truth-teller "in the wild":

(i) A couple of weeks ago, I went to see Spamalot, the musical adaptation of Monty Python and the Holy Grail. One of the songs contained (something close to) the following line: "This is the song that goes like this."

(ii) In the instructions for the Pennsylvania state tax forms, I found (something like) the following:

"You are eligible for the Tax Forgiveness credit if you meet the following requirements:

1. ...
2. ...
3. You meet the eligibility requirements for the Tax Forgiveness Credit.
4. ..."

3/29/2007

Carnap on what's 'really wrong with the Aufbau'

When I was going through some of the photocopied material I have from the Rudolf Carnap archive, I found the following interesting (to me) remark. Carnap is discussing with Nelson Goodman a draft of Goodman's dissertation (A Study of Qualities, which much later became The Structure of Appearance). Goodman points out various supposed technical defects with Carnap's method of quasi-analysis presented in the Aufbau, and Carnap says roughly the following:

The real problem with my Aufbau is not the various counter-examples that can be constructed against my particular version of quasi-analysis (which I already knew about), but rather the assumption of extensionality.

(I haven't quoted, because I don't think it's allowed.) I like this because (a) it's a really smart philosopher saying 'My book rests on a mistake,' and (b) it fits with my pet theory that the real break between Carnap and Quine stems in large part from Carnap moving away from the extensional languages he espoused in Logical Syntax, while Quine held fast to the extensional standard throughout his life (see the posthumous "Confessions of a Confirmed Extensionalist").

3/15/2007

confusion and prokaryotes

One of my recurrent interests is confusion, especially in science. The way I understand this concept is as follows: a term or concept is confused = that term or concept takes 2 or more entities to be one entity (where 'entity' covers individual objects, properties, relations, etc.). In other words, a confused concept or term conflates distinct things. I think the phenomenon of confusion is important in science because part of what happens in many scientific revolutions is that, from the point of view of the new scientific framework, the old scientific framework is confused -- or vice versa. (Re: 'vice versa': Einstein's principle of equivalence, for example, would be seen as an unjustified conflation from the viewpoint of a classical physicist: gravitation and inertia are two separate things, and running them together as Einstein does is an unjustified conflation.)

I've recently started looking at another potential case of confusion in science, but I'm a bit uncertain about it, and would like to air it to get reactions.

In high-school biology class, we are told that the highest/ most basic division among life on Earth is between 2 kingdoms: prokaryotes and eukaryotes. Eukaryotes are all those organisms whose genetic material is encapsulated within a nucleus; Prokaryotes are organisms whose genetic material is not. In other words, Prokaryote=df not-Eukaryote.

However, in the last 2-3 decades, the highest taxonomic level has slowly switched to a three-group classification: Eukaryotes, Archaebacteria, and (Eu)bacteria. Why? The short answer is: "on the molecular level, [archaebacteria] resemble other procaryotes, the eubacteria, no more (probably less) than they do the eukaryotes" (C. Woese et al., PNAS 1990 p.4577).

The upshot for present purposes is that there are actually two distinct highest taxa whose genetic material is not enclosed within a nucleus, viz. the archaebacteria and the eubacteria. From this point of view, it appears that 'prokaryote' conflates the archaebacteria and the eubacteria. But if we recall the earlier characterization of 'prokaryote' as simply 'not-eukaryote,' then 'prokaryote' does not appear to be a confused term. So the question is: Is 'prokaryote' confused, or not? (And why?) I'm happy to hear just intuitions, as well as intuitions backed up with some sort of argument or evidence.

P.s. -- For some readers, this discussion will immediately call to mind Quine's solution to the 'grue' paradox in his paper "Natural Kinds" (in Ontological Relativity and other essays). There, Quine notes that if the predicate P picks out a natural kind, then not-P usually doesn't. A hackneyed example: 'gold' picks out a natural kind (any matter with atomic number 79), but 'not-gold' does not, because it covers many, many completely disparate things -- there are too many ways to be not gold for 'not-gold' to refer to a natural kind.

This might make us think that many/ most predicates of the form not-P are, in fact, confused, since such predicates most often apply to many different natural kinds. All I can say at this point is: that sounds counterintuitive to me... it doesn't feel to me like 'not-gold' conflates distinct things.

3/02/2007

Scott Soames' "Actually" in Vegas

One of my favorite philosophers, Scott Soames, was in Vegas last weekend; he gave a great talk entitled "Actually", and he and his wife Martha took a trip with some of the folks in my department out to the beautiful Valley of Fire state park.

One of the main points Soames pushed was that "actually" plays two very different roles in philosophical semantics. 'Actually p', spoken in a given world W1, means 'p is true in world W1' (sorry, I can't do corner-quotes in Blogger). Now, Soames says there are two ways to specify this world W1:
(1) by picking it out purely indexically, in the way 'I' picks out the speaker of the token, 'now' picks out the moment of utterance, etc. -- so on this way, 'actually p' means 'p is true in THIS world' (or '...in OUR world').

(2) by (roughly- see Soames' paper for the gory details) giving the proposition associated with the Carnapian state-description of W1. (A state-description assigns a value of true or false to every atomic sentence in a language.)

Scott pointed out that if we pick out world W1 in the second way, then 'Actually p' is a priori: once you have a state-description of the world in which that sentence is uttered, then you have all the information you need to figure out its truth-value. This runs contra the conventional wisdom that says 'Actually p' is a posteriori, since we only learn whether p is true in this world via experience; Soames's point was that 'Actually p' is learned via experience when we use way (1) of picking out the world W1, but since there is this other way (2), 'Actually p' is in fact knowABLE a priori, if not knowN a priori in practical cases.

This is very clever, and I need to think more about it, but I think my esteemed colleague James Woodbridge had the best question/ objection of the afternoon. He said 'Actually p' does not just mean 'p is true at world W1,' but rather 'p is true at W1 AND W1 is actual/ instantiated.' Someone could give me the entire state-description of the world we currently inhabit, and then I could calculate from that description that p is true in a world satisfying such a description -- but I still wouldn't know that 'Actually p' is true, because I wouldn't know that the state-description matched this world. (And I was too slow on the uptake to grasp Soames's reply to James.)

My favorite part of Soames's whole talk, though, was the following approximate quotation:
"Perhaps the contingent a priori is just an old wives' tale."
I know I can't get my grandmother to stop talking about Kripke...

2/18/2007

Methodological naturalism without metaphysical naturalism

A student of mine pointed out to me this recent New York Times article. It's about Marcus Ross, who recently received his Ph.D. in geology, writing a perfectly normal geology dissertation about what happened 10-15 million years ago -- except this guy is actually a young earth creationist, that is, he believes the Earth is no more than 10,000 years old, based on a literal interpretation of Genesis. Ross says he works within one "paradigm" when writing his dissertation and working within the geological community, but he does not accept this paradigm for all contexts.

A number of interesting things could be said about this (and many are in the NYT article). I wanted to highlight one of the more philosophical aspects of this case. In the context of the debate over Intelligent Design, the anti-evolutionists often say 'Darwinism is a religious belief (perhaps atheism in disguise).' Many pro-evolutionists respond by drawing a distinction between methodological naturalism and metaphysical naturalism, where only the second is anything close to a religious belief. Here's a rough characterization:

(Methodological Naturalism) Scientific explanations cannot appeal to supernatural causes.

(Metaphysical Naturalism) There are no supernatural causes.

The pro-evolutionists say that science only requires methodological naturalism, not the metaphysical naturalism that is pretty close to atheism. So one could be a methodological naturalist, but need not be a metaphysical naturalist (though presumably not vice versa). One natural response the anti-evolutionist could make is that this distinction is contrived, artificial, or otherwise objectionable.

Well, now Marcus Ross is a striking real-life example of someone who is a methodological naturalist without being a metaphysical naturalist. You might think this would make the pro-evolutionists happy -- but as the NYT article makes clear, not all of them are. There are different reasons for this dissatisfaction (e.g., the young earth creationists can now claim this bona fide geologist is on their side). But one thing that perhaps drives the dissatisfaction is that, to quote the student who showed me this article, this person's beliefs seem "crazy". His mental life seems fragmented or segregated in the extreme.

Somewhat ironically, this case appears to serve as a particularly vivid example in favor of the anti-evolutionists' claim that the distinction between methodological and metaphysical naturalism is bogus. On the other hand, in defense of the distinction, perhaps it is not this geologist's metaphysical supernaturalism that makes his stance seem odd, but rather his further beliefs about the particular, specific nature of the divine causes, viz., creating the Earth 10,000 years ago or so.