On string-acceptability vs. the availability of interpretations, and the "this is the reading therefore this is the structure" gambit

This post is intended as an intellectual provocation. It is the strongest version of a thought I've had knocking around in my head for quite a few years now, but not necessarily a version that I'd be willing to formally defend. Therefore, I urge readers not to lose sight of the fact that this is written in a blog; it is as much an attempt at thinking "out loud" and engaging in conversation as it is an attempt to convince anyone of anything. [Norbert has helped me think through some of these things, but I vehemently absolve him of any responsibility for them, and certainly of any implication that he agrees with me.]

My point of departure for this discussion is the following statement: were the mapping from phonetics to phonology to morphology to syntax to semantics to pragmatics isomorphic – or even 100% reliable – there would be little to no need for linguists. Much of the action, for the practicing linguist, lies precisely in those instances where the mapping breaks down, or is at least imperfect. That doesn't mean, of course, that the assumption that the mapping is isomorphic isn't a valid null hypothesis; it probably is. But an assumption is not the same as a substantive argument.

If you disagree with any of this, I'd be interested to hear it; in what follows, though, I will be taking this as a given.

So here goes...

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The last 15-20 years or so have seen a trend in syntactic argumentation, within what we may broadly characterize as the GB/Principles-and-Parameters/minimalism community, of treating facts about the interpretation of an utterance as dispositive in arguments about syntactic theory.

One response that I've received in the past when conveying this impression to colleagues is that all syntactic evidence is inexorably tied to interpretation, because (i) string-acceptability is just the question of whether utterance A is acceptable under at least one interpretation, and so (ii) string-acceptability is not different in kind from asking whether A is acceptable under interpretation X versus under interpretation Y. In fact, this reasoning goes, there really isn't such a thing as string-acceptability per se, since the task of testing string-acceptability amounts to asking a person, "Can you envision at least one context in which at least one of the interpretations of A is appropriate?"

I think this is too simplistic, since as we all know, there is still a contrast between Colorless green ideas sleep furiously and *Furiously sleep ideas green colorless. But even setting that aside for now, I don't think that the fact that an utterance A has at least one interpretation should be treated (by syntacticians) on a par with the fact that it has interpretation X but not interpretation Y. The reason is that the isomorphic mapping from syntax to semantics (or vice versa, for the purposes of this discussion) is a methodological heuristic, not a substantive argument (see above).

Let's illustrate using an example from locality. Evidence about locality can be gleaned in some instances from string-acceptability alone. That (1) is unacceptable does not depend on a particular interpretation – nor does it even depend on a particular theory of what an interpretation is (i.e., what the primitives of meaning are), for that matter.

(1) *What do you know the delivery guy that just brought us?

I therefore consider the unacceptability of (1) dispositive in syntactic argumentation (well, modulo the usual caveats about acceptability vs. grammaticality, I should say). On the other hand, the fact that (2) can only be interpreted as a question about reasons for knowing, not as a question about reasons for bringing, is not the same type of evidence.

(2) Why do you know the delivery guy that just brought us pizza?

To be clear, they are both evidence for the same thing. But they are not evidence of the same kind. And the provocation offered in this post is that they should not be afforded the same status in distinguishing between syntactic theories.

For the sake of argument, suppose we lived in a world where (2) did have both interpretations, but (1) was still bad. I, as a syntactician, would first try to find a syntactic reason for this. Failing that, however, I would be content with leaving that puzzle for semanticists to worry about. (Perhaps, in this counterfactual world, my semanticist friends would conclude that elements like why can participate in the same kind of semantic relationships that regulate the interaction between the logophoric centers of various clauses? I don't know if that makes any sense. Anyway, I won't try too hard to reason about what other people might do to explain something in a hypothetical world.) More importantly, I'd keep the theory of locality exactly as it is in our world. Obviously the other world would be a less pleasing world to live in. The theory of locality would enjoy less support in this hypothetical world than it does in our world. But the support lost in this counterfactual scenario would be circumstantial, not direct; it is the loss of semantic support for a syntactic theory.

There are (at least) two things you might be asking at this juncture. First, is this distinction real? Aren't we all linguists? Aren't we all after the same thing, at the end of the day? I think the answer depends on granularity. At one level, yes, we're all after the same thing: the nature and properties of that part of our mind that facilitates language. But insofar as we believe that the mechanism behind language is not a monolith; that syntax constitutes a part of it that is separate from interpretation; and that the mapping between the two is not guaranteed a priori to be perfect, then no: the syntactician is interested in a different part of the machine than the semanticist is.

Second, you might be asking this: even if these distinctions are real, why are they important? Why should we bother with them? My answer here is that losing sight of these distinctions risks palpable damage to the health of syntactic theory. Above, I noted that in research on syntax, evidence from interpretation should take a back seat to evidence from string-acceptability. But it feels to me like way too many people are content to posit movement-to-spec-of-TargetInterpretationP (or -ScopeP) without the understanding that, as long as the evidence provided is purely from interpretation, this is really just a semantic theory expressed in syntactic terms. (One might even say it is an 'abuse' of syntactic vocabulary, if one's point were to try and provoke.) This will end up being a valid syntactic theory only to the extent that the aforementioned syntax-semantics (or semantics-syntax) mapping turns out to be transparent. But – and this is the crux of my point – we already know that the mapping between the two isn't always transparent. (As an example, think of semantic vs. syntactic reconstruction.) And so such argumentation should be treated with skepticism, and its results should not be treated as "accepted truths" about syntax unless they can be corroborated using syntactic evidence proper, i.e., string-acceptability.

Another Follow-Up on Athens

Following Norbert's example, I would like to talk a little bit about my experience at the Athens workshop. As you might recall, I was rather sceptical after reading the vision statements that much good would come out of all of this. A week later, my evaluation is more nuanced.

First of all, let me say that I can't think of any other syntax conference I've been to that has been that much fun. The format of brief panel presentations followed by one hour discussions worked incredibly well, much to my own surprise, and the range of topics that were touched on was very diverse (Gillian has a great summary on her blog). That said, I can't shake the feeling that most of the issues people worried about are ultimately small potatoes and that nobody was inclined to really question the foundations of the field, not even as a thought experiment to demonstrate their usefulness. I suppose that puts me in what Gillian calls the Grumpy camp, though I prefer to think of it as a healthy predilection for permanent improvement through criticism. Anyways, let's talk a bit about why all the nice discussions won't bring about any of the changes the field needs, even those everybody in Athens agreed on.

Thomas' way too long comment on the Athens conference

This was originally meant as a comment on the vision statements for the Athens conference, but it just kept growing and growing so I decided to use my supreme contributor powers instead and post it directly to the blog (after an extended moment of hesitation because what I have to say probably won't win me any brownie points).

Since I'm presenting a poster at the conference, I've had access to the statements for a bit longer than the average FoL reader. And that's not a good thing, because they left me seriously worried about the future of the field.

(Just One) More on Interpreting the SMT

One issue I left dangling (relegated to a footnote here actually) is whether to understand the SMT as a methodological or a metaphysical thesis.[1]  The difference lies in evaluating the SMT wrt its fecundity or wrt its truth.  I am partial to the first reading. In fact, I find it hard to see how the metaphysical version of the SMT could be true.  Let me elaborate.

Minimalists like to say that that Minimalism is a program, not a theory.  I actually have some reservations about this claim for programs are vindicated to the degree that they generate interesting and true theories, if not right away, then over a reasonable time span.  The Minimalist Program (MP) is now approximately 20 years old, so we should by now be evaluating it in terms of its theories.[2]  As I believe that there are a lot of pretty good and empirically interesting (even true) proposals that the program has generated, I think that the “program” line can sometimes be a dodge.  However, whether this is true or not, there is something important about the ‘program’ vs ‘theory’ distinction that is relevant to what I want to say here. The main distinction between programs and theories is that theories are things that can be true or false whereas programs are things that are fertile or sterile.  As such, programs generate research methodologies, ways of approaching questions that can lead to theories that are truth evaluable.  And one important feature of a good program is that the methodologies do actually function as productive hypothesis generators.  One of the features of minimalism from the get-go has been its ability to suggest interesting avenues of linguistic investigation.  It has done so in several ways.[3]

First, as Chomsky has liked to stress, it keeps us honest.  Often our explanations are the same order of complexity as the phenomena they aim to explain.  This may or may not be useful (re-describing something can be a crucial step to explaining it), however, it is unlikely to be explanatory.  It’s never a good idea to explain N data points with a theory that has N degrees of freedom.  At any rate, early minimalism stressed the methodological virtues of simplicity and elegance and tried to motivate how they might be operationalized in the context of late GB syntax.  Chomsky’s 1993 paper[4], the one that launched the enterprise, was a very good guide of how to do this, deploying Ockham’s razor to great effect in cutting away some GB underbrush.  Chomsky’s basic point was methodological viz. if we want our explanations to explain then they cannot be as convoluted as the data they care about.  And he observed that firmly keeping this in focus can lead to a significant explanatory boost, i.e. less can be more, a whole lot more.

Second, MP started people (like me) thinking about the virtues of reduction/unification.  Though never absent even in earlier work, this kind of project makes deep sense in the minimalist context. Why? Precisely because it urges that we go “beyond explanatory adequacy,” to use Chomsky’s terms. GB was mainly concerned with Plato’s problem. This problem is “solved” once something is put into UG for by assumption things in UG need not be learned. This often has the effect (I am confessing here) of removing the incentive for developing swelt, streamlined, elegant accounts. So long as the principles can be shoved into UG their ungainliness fails to generate much empirical friction. To put it crudely (something many of you might think I do all too well) GB theories were to elegance what the lunar module was to aerodynamics (Did you ever see the damn thing? It looks like a pile of mechanical garbage wrapped in tin foil, see here) and roughly for the same reason. The module didn’t need to be nicely shaped to move efficiently through space as way out there space is a frictionless medium. In a sense, that was also true of GB; once inside UG, the shape of the principles didn’t much matter for Plato’s Problem. 

Now I don’t want to overstate this. Linguists have always cared about elegance, simplicity, redundancy, etc. However, MP greatly raised the status of these virtues. These virtues fueled the impulse to unify the principles of UG and unification became empirically important when one worried not only about learnability issues but also about how FL/UG itself might have arisen. I’ve talked about this (no doubt too much, but as you can see I am obsessed by this) elsewhere (here) so I will drop the issue now. But I bring it up because it bears on the correct interpretation of the SMT. 

One way of thinking about the SMT is along the lines of these more general desiderata.  In other words, the SMT is an injunction to look for examples where interface properties reveal representational structure. The PLHH work shows that the ANS+visual system can tell us quite a bit about the nature of semantic representations (aka linguistic meaning) and work on parsing and acquisition can do so as well wrt syntactic representations.  When such things are found, they can be revealing and the SMT, viewed as a methodological precept to look for such, can be, and has been, quite fecund, especially in forcing different kinds of linguists (syntacticians, phonologists, psycho types, and even neuro types) to ask how their projects and assumptions fit together. In short, as a guiding methodological principle, the SMT is a winner: fecund? Check ✔.

What about a metaphysical thesis?  Here, things get a whole lot murkier.  Recall that the SMT is supposed to be the thesis that the grammar is the optimal solution to interface conditions.  One way of reading this is that the interfaces cause linguistic representations to have the properties they do. But what would it mean for this to be true?  I really don’t know.

There is one possibility, the standard Darwinian one in which over long periods of time the interfaces chisel away at the rough edges of FL/UG (and vice versa) till they fit snugly together (interface requirements accommodating themselves to features of FL/UG and properties of FL/UG accommodating themselves to features of the interfaces).  Maybe, but recall a good deal of Darwin’s Problem in MP rests on the premise that FL/UG popped up pretty quickly and so there was no time for the Darwin’s selectionist mutual accommodation to effectively operate.  Without this Darwininan solvent, any fit that exists between interfaces and FL/UG will be quite adventitious.  In fact, I would expect such perfect fit to be the exception rather than the rule and I expect that there will be/are many many interfaces with which the resources of FL don’t integrate at all well with systems that (try to) use them.  I can personally attest to the fact that my “dance module” is almost completely inured to verbal instruction. So, as a metaphysical thesis, I see no reason to believe that the SMT is even roughly correct. Or if it is correct it is total mystery why it is or even could be.  It would be too damn amazing were FL/UG to be just what every interface ordered. This would be super-intelligent design! This is why I find the SMT to be a pretty poor metaphysical thesis: from where I sit, it has all the hallmarks of being obviously false (indeed, incredible).

Is there anything paradoxical about a principle being methodologically fecund though metaphysically false? Nope. Fecundity and truth are related but distinct evaluative dimensions.  To repeat: programs/methodologies fecund, theories/proposals true/false. So qua methodological precept (viz. look for this!) the SMT is a powerful injunction, but qua metaphysical thesis, not so much.

Let me put this another way by considering an analogy between the SMT and the Anthropic Principle (AP) (here).  The AP can be used to deduce the values of attested physical constants. How? Well, the values must lie within a certain range in order for (conscious) life to be possible. As the universe clearly contains (conscious) life (i.e. us, well on some days at least) this fact can be used to specify a narrow range of values for the attested physical constants (e.g. the fine structure constant).  As a methodological principle, AP seems unexceptionable. Given that we are here, of course the universe must be hospitable to us and this means that the physical constants must have hospitable-for-us values.  However, as a metaphysical principle AP has a decidedly mystical air (e.g. the universe is “compelled, in some sense, for conscious life to emerge” (Wikipedia). Note the “in some sense,” always a sign that things are getting weird) that has a distinct theistic odor suggesting intelligent design. The SMT is similar. If FL’s products fit an interface transparently there is a lot to learn about the fine structure of the representation.  However, this is not because the interface causes linguistic representations to have the features they do but because in the domains where the SMT holds features of the interface and features of the representations are very closely correlated.  Thus, knowing the properties of one can tell you a lot about the properties of the other. In other words, where the SMT holds features of the interface can be used to probe features of the linguistic representation. And just as our existence has implications for the values of the physical constants (at least in our universe) per AP, so too do properties of SMT compliant interfaces have implications for the properties of linguistic representations, even if metaphysically speaking both the AP and the SMT are false. [5]

In sum, even if the general metaphysical version of the SMT is false, there is reason to hope that some interfaces will fit with FL/UG tightly. The properties of these can then be used to plumb the internal details of FL/UG (and, of course, vice versa).  These domains of investigation will then be closely integrated, allowing for the development of richer theories of both FL/UG and the relevant interface. 

Methodologically, one can go a little further and elevate the SMT to a methodological ideal. In particular, we can take as a default assumption that, for any given interface, the SMT (viz. the Transparency Thesis) holds. It should be easyish to disconfirm this if false (and I suspect that it will be often false), so it is a good 0-th level assumption to make.  In the meantime, whether the SMT holds or not for a particular interface, we will find something interesting, and that’s what makes it an ideal methodological principle.

No doubt, there are other interpretations of the SMT that are more metaphysically charged (see Introduction of this for example).  There are times when Chomsky’s allusions to third factors and snowflakes can carry this kind of tinge (there are also times when he resiles from this interpretation and explicitly adopts a methodological stance wrt MP and its precepts).  For me, it is comforting to be able to interpret the various programmatic precepts in methodological terms. Why? I understand these and can see how to use them to generate research hypotheses. Seen from this perspective, the SMT is a very good way of framing linguistic questions, even if it is metaphysically very far fetched.[6]

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[1] This post developed from conversations that I had with Paul (the ‘P’ in PLHH) about the Interface Transparency Thesis and the SMT. It goes without saying that he is completely responsible for any dumb ass thing that I say here. Don’t like it, complain to him.

[2] A possible counter is that it’s too early to engage minimalist themes. Perhaps. But if so, then it’s not really a program either, more like a vision or dream.

[3] I’ve discussed this here for those interested.

[4] Epstein’s paper on c-command (here) was also very good at making these points.

[5] Now for a mea culpa (footnotes are good for this): (here) I said that the features of the ANS+visual system explain the features of L.  This strongly suggests that they are the cause of those features in L. If the above is right, this is very misleading and I accept full responsibility for misleading you.  I am so contrite that I am sure you will all forgive me. Thx for your indulgence. What we can say is that given the ITT we can deduce some features of L by noting features of ANS+visual, but in this case deducing X does not amount to explaining L (think heights of flagpoles and the shadows they cast).

[6] Curiously, this is the converse with the most vociferous versions of Linguistics Platonism: whatever its metaphysical virtues (none in my view) the methodological consequences of adopting it are confusing at best and baneful at worst (see here).