Strings and sets

I have argued repeatedly that the Minimalist Program (MP) should be understood as subsuming earlier theoretical results rather than replacing them. I still like this way of understanding the place of MP in the history of GG, but there is something misleading about it if taken too literally. Not wrong exactly, but misleading. Let me explain.

IMO, MP is to GB (my favorite exemplar of an earlier theory) as Bounding Theory is to Ross’s Islands. Bounding Theory takes as given that Ross’s account of islands is more or less correct and then tries to derive these truths from more fundamental assumptions.[1] Thus, in one important sense, Bounding Theory does not substitute for Ross’s but aims to explain it. Thus, Bounding Theory aims to conserve the results of Ross’s theory more or less.[2] 

Just as accurately, however, Bounding Theory does substitute for Ross’s. How so? It conserves but does not recapitulate it. Rather it explains why the things on Ross’s list are there. Furthermore, if successful it will add other islands to Ross’s inventory (e.g. Subject Condition effects) and make predictions that Ross’s did not (e.g. successive cyclicity). So conceived, Ross’s island are explanada for which Bounding Theory is the explanans.

Note, and this is important, given this logic Bounding Theory will inherit any (empirical) problems for Ross’s generalizations. Pari passu for GB and MP. I mention this not because it is the topic of todays sermonette, but just to observe that many fail to appreciate this when criticizing MP. Here’s what I mean.

One way MP might fail is in adopting the assumption that GBish generalizations are more or less accurate. If this assumption is incorrect, then the MP story fails in its presuppositions. And as all good semanticists know, this is different from failing in one’s assertions. Failing this way makes you not so much wrong as uninteresting. And MP is interesting, just as Bounding Theory is interesting, to the degree that what it presupposes is (at least) on the right track.[3]

All of this is by way of (leisurely) introduction to what I want to talk about below. Of the changes MP has suggested I believe that most (or, to be mealy mouthed, one of the most) fundamental has been the proposal that we banish strings as fundamental units of grammar. This shift has been long in coming, but one way of thinking about Chomsky’s set theoretic conception of Merge is that it dislodges concatenation as the ontologically (and conceptually) fundamental grammatical relation. Let me flesh this out a bit.

The earliest conception of GG took strings as fundamental, strings just being a series of concatenated elements. In Syntactic Structures (SS) (and LSLT for which SS was a public relations brochure) kernel sentences were defined as concatenated objects generated by PS rules. Structural Descriptions took strings as inputs and delivered strings (i.e. Structural Changes) as outputs (that’s what the little glide symbol (which I can’t find to insert) connecting expressions meant). Thus, for example, a typical rule took as input things like (1) and delivered changes like (2), the ‘^’ representing concatenation. PS rules are sets of such strings and transformations are sets of sets of such strings. But the architecture bottoms out in strings and their concatenative structures.[4]

(1)  X^DP₁^Y^V^DP₂^Z

(2)  X^DP₂^Y^V+en^by^NP₁

This all goes away in merge based versions of MP.[5] Here phrase markers (PM) are sets, not strings and string properties arise via linearization operations like Kayne’s LCA which maps a given set into a linearized string. The important point is that sets are what the basic syntactic operation generates, string properties being non-syntactic properties that only obtain when the syntax is done with its work.[6] It’s what you get as the true linguistic objects, the sets, get mapped to the articulators. This is a departure from earlier conceptions of grammatical ontology.

This said it’s an idea with many precursors. Howard Lasnik has a terrific little paper on this in the Aspects 50 years later (Gallego and Ott eds, a MITWPL product that you can download here). He reviews the history and notes that Chomsky was quite resistant in Aspects to treating PMs as just coding for hierarchical relationships, an idea that James McCawley, among others, had been toying with. Howard reviews Chomsky’s reasoning and highlights several important points that I would like to quickly touch on here (but read the paper, it’s short and very very sweet!).

He notes several things. First, that one of the key arguments for his revised conception in Aspects revolved around eliminating some possible but non-attested derivations (see p. 170). Interestingly, as Howard notes, these options were eliminated in any theory that embodied cyclicity. This is important for when minimalist Chomsky returns to Generalized Transformations as the source of recursion, he parries the problems he noted in Aspects by incorporating a cyclic principle (viz. the Extension Condition) as part of the definition of Merge.[7]

Second, X’ theory was an important way station in separating out hierarchical dependencies from linear ones in that they argued against PS rules in Gs. By dumping PS rules, the relation between such rules and the string features of Gs was conceptually weakened.

Despite this last point, Lasnik’s paper highlights the Aspects arguments against set based conception of phrase structure (i.e in favor of retaining string properties in PS rules). This is section 3 of Howard’s paper. It is a curious read for a thoroughly modern minimalist for in Aspects we have Chomsky arguing that it is a very bad idea to eliminate linear properties from the grammar as was being proposed, by among others, James McCawley. Uncharacteristically (and I mean this is a compliment), Chomsky’s reasoning here is largely empirical. Aspects argues that when one looks, the Gs of the period, presupposed some conception of underlying order in order to get the empirical facts to fit and that this presupposition fits very poorly with a set theoretic conception of PMs (see Aspects: 123-127). The whole discussion is interesting, especially the discussion of free word order languages and scrambling. The basic observation is the following (126):

In every known language the restrictions on order [even in scrambling languages, NH] are quite severe, and therefore rules of realization of abstract structures are necessary. Until some account of such rules is suggested, the set-system simply cannot be considered seriously as a theory of grammar.

Lasnik, argues plausibly, that Kayne’s LCA offered such an account and removed this empirical objection against eliminating string information from basic syntactic PMs.

This may be so. However, from my reading of things I suspect that something else was at stake. Chomsky has not, on my reading, been a huge fan of the LCA, at least not in its full Kaynian generality (see note 6). As Howard observes, what he has been a very big fan of is the observation, going back at least to Reinhart, that, as he says in the Black Book (334), “[t]here is no clear evidence that order plays a role at LF or in the computation from N [numeration, NH] to LF.”

Chomsky’s reasoning is Reinhart’s on steroids. What I mean is that Reinhart’s observations, if memory serves, are largely descriptive, noting that anaphora is largely insensitive to order and that c-command is all that matters in establishing anaphoric dependencies (an important observation to be sure and one that took some subtle argumentation to establish).[8] Chomsky’s observations go beyond this in being about the implications of such lacunae for a theory of generative procedures. What’s important wrt to linear properties and Gs is not whether linearized order plays a discernible role in languages, of course it does, but whether these properties tell us anything about generative procedures (i.e. whether linear properties are factors in how generative procedures operate). This is key. And Chomsky’s big claim is that G operations are exclusively structure dependent, that this fact about Gs needs to be explained and that the best explanation is that Gs have no capacity to exploit string properties at all. This builds on Reinhart, but is really making a theoretical point about the kinds of rules/operations Gs contain rather than a high level observation about antecedence relations and what licenses them.

So, the absence of linear sensitive operations in the “core” syntax, the mapping from lexical items to “LF” (CI actually, but I am talking informally here) rather than some way of handling the evident linear properties of language, is the key thing that needs explanation.

This is vintage Chomsky reasoning: look for the dogs that aren’t barking and give a principled explanation for why they are not barking. Why no barking strings? Well, if PMs are sets then we expect Gs to be unable to reference linear properties and thus such information should be unable to condition the generative procedures we find in Gs.

Note that this argument has been a cynosure of Chomsky’s most recent thoughts on structure dependence as well. He reiterates his long-standing observation that T to C movement is structure dependent and that no language has a linear dependent analogue (move the “highest” Aux exists but move the “left-most” aux never does and is in fact never considered an option by kids building English Gs). He then goes on to explain why  no G exploit such linear sensitive rules. It’s because the rule writing format for Gs exploits sets and sets contain no linear information. As such rules that exploit linear information cannot exist for the information required to write them is un-codeable in the set theoretic “machine language” available for representing structure. In other words, we want sets because the (core) rules of G systematically ignore string properties and this is easily explained if such properties are not part of the G apparatus.

Observe, btw, that it is a short step from this observation to the idea that linguistic objects are pairings of meanings with sounds (the latter a decidedly secondary feature) rather than a pairing of meanings and sounds (where both interfaces are equally critical). These, as you all know, serve as the start of Chomsky’s argument against communication based conceptions of grammar. So eschewing string properties leads to computational rather than communicative conceptions of FL.

The idea that strings are fundamental to Gs has a long and illustrious history. There is no doubt that empirically word order matters for acceptability and that languages tolerate only a small number of the possible linear permutations. Thus, in some sense, epistemologically speaking, the linear properties of lexical objects is more readily available (i.e. epistemologically simpler) than their hierarchical ones. If one assumes that ontology should follow epistemology or if one is particularly impressed with what one “sees,” then taking strings as basic is hard to resist (and as Lasnik noted, Chomsky did not resist it in his young foolish salad days). In fact, if one looks at Chomsky’s reasoning, strings are discounted not because string properties do not hold (they obviously do) but because the internal mechanics of Gs fails to exploit a class of logically possible operations. This is vintage Chomsky reasoning: look not at what exists, but what doesn’t. Negative data tells us about the structure of particular Gs. Negative G-rules tells us about the nature of UG. Want a pithy methodological precept? Try this: forget the epistemology, or what is sitting there before your eyes, and look at what you never see.

Normally, I would now draw some anti Empiricist methodological morals from all of this, but this time round I will leave it as an exercise for the reader. Suffice it for now to note that it’s those non-barking dogs that tell us the most about grammatical fundamentals.

---

[1] Again, our friends in physics make an analogous distinction between effective theories (those that are more or less empirically accurate) and fundamental theories (those that are conceptually well grounded). Effective theory is what fundamental theory aims to explain. Using this terminology, Newton’s theory of gravitation as the effective theory that Einstein’s theory of General Relativity derived as a limit case.

[2] Note that conserving the results of earlier inquiry is what allows for the accumulation of knowledge. There is a bad meme out there that linguistics in general (and syntax in particular) “changes” every 5 years and that there are no stable results. This is hogwash. However, the misunderstanding is fed by the inability to appreciate that older theories can be subsumed as special cases by newer ones.  IMO, this has been how syntactic theory has generally progressed, as any half decent Whig history would make clear. See one such starting here and continuing for 4 or 5 subsequent posts.

[3] I am not sure that I would actually strongly endorse this claim as I believe that even failures can be illuminating and that even theories with obvious presuppositional failures can point in the right direction. That said, if one’s aim is “the truth” then a presupposition failure will at best be judged suggestive rather than correct.

[4] For those that care, I proposed concatenation as a primitive here, but it was a very different sense of concatentation, a very misleading sense.  I abstracted the operation from string properties. Given the close intended relation between concatenation and strings, this was not a wise move and I hereby apologize.

[5] I have a review of Merge and its set like properties in this forthcoming volume for those that are interested.

[6] One important difference between Kayne’s and Chomsky’s views of linearization is that the LCA is internal to the syntax for the former but is part of the mapping from the syntax proper to the AP interface for the latter. For Kayne, LCA has an effect on LF and derives the basic features of X’ syntax. Not so for Chomsky. Thus, in a sense, linear properties are in the syntax for Kayne but decidedly outside it for Chomsky.

[7] The SS/LSLT version of the embedding transformation was decidedly not cyclic (or at least not monotonic structurally). Note, that other conceptions of cyclicity would serve as well, Extension being sufficient, but not necessary.

[8] It’s also not obviously correct. Linear order plays some role in making antecedence possible (think WCO effects) and this is surely true in discourse anaphora. That said, it appears that in Binding Theory proper, c-command (more or less), rather than precedence, is what counts.

Aspects at 50

Here is a piece (here) by Geoff Pullum (GP) celebrating the 50^th anniversary of Aspects. This is a nice little post. GP has a second post that he mentions in the one linked to on the competence/performance distinction. I’ll put up a companion piece to this second post anon. Here are a few comments on GP’s Aspects post.

Here GP gives a summary that feels right to me (i.e. my recollections match GP’s) about the impact that Aspects had on those that first read it. Reading chapter 1 felt revelatory,  like a whole new world opening up. The links that it forged between broad issues in philosophy (I was an undergrad in philosophy when I first read it) and central questions in cognition and computation were electrifying. Everyone in cognition broadly construed (and I do mean everyone: CSers, psychologists, philosophers) read Aspects and believed that they had to read it. Part of this may have been due to some terminological choices that Chomsky came to regret (or so it I believe). For example, replacing the notion “kernel sentence” with the notion “deep structure” led people to think, as GP put it:

Linguistics isn’t a matter of classifying parts of sentences anymore; it was about discovering something deep, surprising and hidden.

But this was not the reason for its impact. The reason Aspects was a go-to text was that chapter 1 was (and still is) a seminal document of the Cognitive Revolution and the study of mind. It is still the best single place to look if one is interested in how the study of language can reveal surprising, non-trivial features about human minds. So perhaps there is something right about the deep in Deep Structure. Here’s what I mean.

I believe that Chomsky was in a way correct in his choice of nomenclature. Though Deep Structure itself was/is not particularly “deep,” understanding the aim of syntax as that which maps between phrase markers that represent meaning-ish information (roughly thematic information, which, recall, was coded at Deep Structure)[1] with structures that feed phonetic expression is deep. Why? Because, such a mapping is not surface evident and it involves rules and abstract structure with their own distinctive properties.  Aspects clarifies what is more implicit in Syntactic Structures (and LSLT, which was not then widely available); namely that syntax manipulates abstract structures (phrase markers). In particular, in contrast to Harris, who understood Transformations as mapping sentences (actually items in a corpus (viz. utterances)) to sentences, Aspects makes clear this is not the right way to understand transformations or Gs. The latter map phrase markers to other phrase markers and eventually to representations of sound and meaning. They may map relations between sentences, but only very indirectly. And this is a very big difference in the conception of what a G is and what a transformation is, and it all arises in virtue of specifying what a Deep Structure is. In particular, whereas utterances are plausibly observable, the rules that do the mappings that Chomsky envisaged are not. Thus, what Aspects did was pronounce that the first object of linguistic study is not what you see and hear but the rules, the Gs that mediate two “observables”: what a sentence means and how it is pronounced. This was a real big deal, and it remains a big deal (once again, reflect on the difference between Greenberg and Chomsky Universals). As GP said above, Deep Structure moves us from meditating on sentences (actually, utterances or items in corpora) to thinking about G mappings.

Once one thinks of things in this way, then the rest of the GG program follows pretty quickly: What properties do Gs have in common? How are Gs acquired on the basis of the slim evidence available to the child? How are Gs used in linguistic behavior? How did the capacity to form Gs arise in the species? What must G capable brains be like to house Gs and FL/UGs? In other words, once Gs become the focus of investigation, then the rest of the GG program comes quickly into focus. IMO, it is impossible to understand the Generative Program without understanding chapter 1 of Aspects and how it reorients attention to Gs and away from, as GP put, “classifying parts of sentences.”

GP also points out that much of the details that Aspects laid out have been replaced with other ideas and technology. There is more than a little truth to this. Most importantly, in retrospect, Aspects technology has been replaced by technicalia more reminiscent of the the Syntactic Structures (SS)-LSLT era. Most particularly, we (i.e. minimalists) have abandoned Deep Structure as a level. How so?

Deep Structure in Aspects is the locus of G recursion (via PS rules) and the locus of interface with the thematic system. Transformations did not create larger phrase markers, but mapped these Deep Structure PMs into others of roughly equal depth and length.[2] In more contemporary minimalist theories, we have returned to the earlier idea that recursion is not restricted to one level (the base), but is a function of the rules that work both to form phrases (as PS rules did in forming Deep Structure PMS) and transform them (e.g. as movement operations did in Aspects). Indeed, Minimalism has gone onse step further. The contemporary conceit denies that there is a fundamental distinction between G operations that form constituents/units and those that displace expressions from one position in a PM to another (i.e. the distinction between PS rules and Transformations). That’s the big idea behind Chomsky’s modern conception of Merge, and it is importantly different from every earlier conception of G within Generative Grammar. Just as LGB removed constructions as central Gish objects, minimalism removed the PS/Transformation rule distinction as a fundamental grammatical difference. In a merge based theory there is only one recursive rule and both its instances (viz. E and I merge) build bigger and bigger structures.[3]  

Crucially (see note 3), this conception of structure building also effectively eliminates lexical insertion as a distinct G operation, one, incidentally, that absorbed quite a bit of ink in Aspects. However, it appears to me that this latter operation may be making a comeback. To the degree that I understand it, the DM idea that there is late lexical insertion comes close to revitalizing this central Aspects operation. In particular, on the DM conception, it looks like Merge is understood to create grammatical slots into which contents are later inserted. This distinction between an atom and the slot that it fills is foreign to the original Merge idea. However, I may be wrong about this, and if so, please let me know. But if so, it is a partial return to ideas central to the Aspects inventory of G operations.[4]

In addition, in most contemporary theories, there are two other lasting residues of the Aspects conception of Deep Structure. First, Deep Structure in Aspects is the level where thematic information meets the G. This relation is established exclusively by PS rules. This idea is still widely adopted and travels under the guise of the assumption that only E-Merge can discharge thematic information (related to the duality of interpretation assumption). This assumption regarding a “residue” of Deep Structure, is the point of contention between those that debate whether movement into theta positions is possible (e.g. I buy it, Chomsky doesn’t). [5] Thus, in one sense, despite the “elimination” of DS as a central minimalist trope, there remains a significant residue that distinguishes those operations that establish theta structure in the grammar and those that transform these structures to establish the long distance displacement operations that are linguistically ubiquitous.[6]

Second, all agree that theta domains are the smallest (i.e. most deeply embedded) G domains. Thus, an expression discharges its thematic obligations before it does anything else (e.g. case, agreement, criterial checking etc.). This again reflects the Aspects idea that Deep Structures are inputs to the transformational component. This assumption is still with us; despite the “elimination” of Deep Structure. We (and here I mean everyone, regardless of whether you believe that movement to a theta position is licit) still assume that a DP E-merges into a theta position before it I-merges anywhere else, and this has the consequence that the deepest layer of the grammatical onion is the theta domain. So far as I know, this assumption is axiomatic. In fact, why exactly sentences are organized so that the theta domain is embedded in case/agreement domain, which is in turn embedded in A’-domains is entirely unknown.[7]

In short, Deep Structure, or at least some shadowy residue, is still with us, though in a slightly different technical form. We have abandoned the view that all thematic information is discharged before any transformation can apply. But we have retained the idea that for any given “argument” its thematic information is discharged before any transformation applies to it, and most have further retained the assumption that movement into theta positions is illicit. This is pure Deep Structure.

Let me end by echoing GP’s main point. Aspects really is an amazing book, especially chapter 1. I still find it inspirational and every time I read it I find something new. GP is right to wonder why there haven’t been countless celebrations of the book. I would love to say that it’s because its basic insights have been fully absorbed into linguistics, and the wider cognitive study of language. It hasn’t. It’s still, sadly, a revolutionary book. Read it again and see for yourself.

---

[1] Indeed, given the Katz-Postal hypothesis all semantic information was coded at Deep Structure. As you all know, this idea was revised in the early 70s with both Deep Structure and Surface Structure contributing to interpretation. Thematic information still coded in the first and scope information and binding and other semantic effects coded in the second. This led to a rebranding, with Deep Structure giving way to D-Structure. This more semantically restricted level was part of every subsequent mainstream generative G until the more contemporary Minimalist period. And, as you will see below, it still largely survives in modified form in thoroughly modern minimalist grammars.

[2] “Roughly” because there were pruning rules that made PMs smaller, but none that made them appreciably bigger.

[3] In earlier theories PS rules built structures that lexical insertion and movement operations filled. The critical feature of Merge that makes all its particular applications structure building operations is the elimination of the distinction between an expression and the slot it occupies. Merge does not first form a slot and then fill it. Rather expressions are combined directly without rules that first form positions into which they are inserted.

[4] Interestingly, this makes “traces” as understood within GB undefinable, and this makes both the notion of trace and that of PRO unavailable in a Merge based theory. As the rabbis of yore were found of mumbling: Those who understand will understand.

[5] Why only E-merge can do so despite the unification of E and I merge is one of the wedges people like me use to conceptually motivate the movement theory of control/anaphora. Put another way, it is only via (sometimes roundabout) stipulation that a minimalist G sans Deep Structure can restrict thematic discharge to E-merge.

[6] In other words, contrary to much theoretical advertising, DS has not been entirelyeliminated in most theories, though one central feature ahs been dispensed with.

[7] So far as I know, the why question is rarely asked. See here for some discussion and a link to a paper that poses and addresses the issue.

Joining the Fun; A Ramble on Parameters

There a very interesting pair of posts and a long thread of insightful comments relating to parameters, both the empirical support for such as well as their suitability given current theoretical commitments.  Cederic, commenting on Neil’s initial post and then adding a longer elaboration, makes the point that nobody seems committed to parameters in the classical sense anymore. Avery and Alex C comment that whatever the empirical shortcomings of parameteric accounts, something is always better than nothing so they reasonably ask what do we replace it with. Alex D rightly points out that the success of parametric accounts is logically independent of the POS and claims about linguistic nativism. In this post, I want to reconstruct the history of how parameter theory arose so as to consider where we ought to go from here. The thoughts ramble on a bit, because I have been trying to figure this out for myself.  Apologies ahead of time.

In the beginning there was the evaluation metric (EM), and Chomsky looked on his work and saw that it was deficient.  The idea in Aspects was that there is a measure of grammatical complexity built into FL and that children in acquiring their I-language (an anachronism here) chose the simplest one compatible with the PLD (viz. the linguistic data available to and used by the child). EM effectively ordered grammars according to their complexity. The idea riffed on ideas of minimal description length around at the time but with the important addition that the aim of a grammatical theory with aspirations of explanatory adequacy was to find the correct UG for specifying the meta-language relevant to determining the correct notion of “description” and “length” in minimal description length. The problem was finding the right things to count when evaluating grammars. At any rate, on this conception, the theory of acquisition involved finding the best overall G compatible with PLD as specified by EM.  Chomsky concluded that this conception, though logically coherent, was not feasible as a learning theory, largely because it looked to be computationally intractable.  Nobody had (nor I believe, has) a good tractable idea of how to compare grammars overall so as to have a complete ordering. Chomsky in LSLT developed some pair-wise metrics for the local comparison of alternative rules, but this is a long way from having a total ordering of the alternative Gs that is required to make EM accounts feasible.  Chomsky’s remedy for this problem: divorce language acquisition from the evaluation of overall grammar formats.

The developments of the Extended Standard Theory, which culminated in GB theories, allows for an alternative conception of acquisition, one that divorces it from measuring overall grammar complexity.  How so? Well, first we eliminated the idea that Gs were compendia of constructions specific rules. And second, we proposed that UG consists of biologically provided schemata (hence part of UG and hence not in need of acquisition) that specify the overall shape of a particular G. On this view, acquisition consists in filling in values for the schematic variables.  Filling in values of UG specified variables is a different task from figuring out the overall shape of the grammar and, on the surface at least, a far more tractable task. The number of parameters being finite already distinguished this from earlier conceptions. In the earlier EM view of things there was no reason to think that the space of grammatical possibilities was finite. Now, as Chomsky emphasized, within a parameter setting model, the space of alternatives, though perhaps very large, was still finite and hence the computational problem was different in kind from the one lightly limned in Aspects. So, divorcing the question of grammatical formats (via the elimination of rules or their reduction to a bare minimum form like ‘move alpha’) from the question of acquisition allowed for what looked like a feasible solution to Plato’s Problem. In place of Gs being sets of constructions specific rules with EMs measuring their overall collective fitness, we had the idea that Gs were vectors of UG specified variables with two possible values (and hence “at most” 2ⁿ possible grammars, a finite number of options). Finding the values was divorced from evaluating sets of rules and this looked feasible.

Note that this is largely a conceptual argument. There is a reasonable hunch but no “proof.” I mention this because other conceptual considerations (we will get to them) can serve to challenge the conclusion and make parameter theories less appealing.

In addition to these conceptual considerations, the comparative grammar research in the 70s, 80s, and 90s provided wow-inducing empirical confirmation of parameter based conceptions. It is hard for current (youngish) practitioners of the grammatical dark arts to appreciate how exciting early work on parameter setting models was. There were effectively three lines of empirical support.

1.     The comparative synchronic grammar research. For example:

a.     The S versus S’ parameter distinguishing Italian from English islands (Rizzi, Sportiche, Torrego)).

b.     The pro drop parameter (correlating, null subjects, inversion and long movement apparently violating the fixed subject/that-t condition (Rizzi, Brandi and Cordin)).

c.     The parametric discussions of anaphoric classes (local and long distance anaphors (Wexler, Borer), to name just three, all uncovered a huge amount of new linguistic data and argued for the fecundity of parametric thinking.

2.     Crain’s “continuity thesis,” which provided evidence that kids “mistakes” in acquiring their particular Gs all actually conform to actual adult Gs. This provided evidence that the space of G options was pretty circumscribed, as a parameter theory implies it is.

3.     The work on diachronic change by Kroch, Lightfoot, Roberts (and more formal work by Berwick and Niyogi) a,o., which indicated that large shifts in grammatical structure over time (e.g. SOV to SVO) could be analyzed as changes in a small number of simple parameter changes.

So, there was a good conceptual reason for moving to parameter models of UG and the move proved to be empirically very fecund. Why the current skepticism?  What’s changed?

To my mind, three changes occurred. As usual, I will start with the conceptual challenges and then proceed to the empirical ones.

The first one can be traced to work first by Dresher and Kaye, and then taken up and further developed with great gusto by Fodor (viz. Janet) and Sakas. This work shows that finite parameter setting can present tractability problems almost as difficult as the ones that Chomsky identified in his rejection of EM models.  What this work demonstrates is that given current envisioned parameters, parameter setting cannot be incremental. Why not? Because parameter values are not independent.  In other words, the value of one parameter in a particular G may depend crucially on that of another. Indeed, the value of any may depend on the value of each and this makes for an explosive combinatory problem. It also makes incremental acquisition mysterious; how do the parameter values get set if any bit of later PLD can completely overturn values previously set?

There have been ingenious solutions to this problem, my favorite being cue-based conceptions (developed by Dresher, Fodor, Lightfoot a.o.). These rely on the notion that there is some data in the PLD that unambiguously determines the value of a parameter. Once set on the basis of this data, the value need never change.  Triggers effectively impose independence on the parameter space. If this is correct, then it renders UG yet more linguistically specific; not only are the parameters very linguistically specific, but the apparatus required to fix these is very linguistically specific as well. Those that don’t like linguistically parochial UGs should really hate both parameter theories and this fix to them. Which brings us to the second conceptual shift: Minimalism.

The minimalist conceit is to eliminate the parochialism of FL and show that the linguistically specific structure of UG can be accounted for in more general cognitive/computational terms. This is motivated both on general methodological grounds (factoring out what is cognitively general from what is linguistically specific is good science) and as a first step to answering Darwin’s Problem, as we’ve discussed at length in other posts. FL internal parameters are a very big challenge to this project. Why? Because UG specified parameters encumber FL with very linguistically specific information (e.g. it’s hard to see how the pro drop parameter (if correct) could possibly be stated in non linguistically specific terms!).

This is what I meant earlier when I noted that conceptual reasons could challenge Chomsky’s earlier conceptual arguments.  Even if parameters made addressing Plato’s Problem more tractable, they may not be a very good solution to the feasibility problem if they severely compromise any approach to Darwin’s. This is what motivates Cederic’s concerns (and others, e.g. Terje Lohndal) I believe, and rightly so.  So, the conceptual landscape has changed and it is not surprising that parameter theories have become less appealing and so open to challenge.

Moreover, as Cederic also stresses, the theoretical landscape has changed as well. A legacy of the GB era that has survived into Minimalism is the agreement that Gs do not consist of construction based rules. Rather, there are very general operations (Merge) with very general constraints (e.g. Extension, Minimality) that allow for a small set of dependencies universally.  Much of this (not all, but much) can be reanalyzed in non linguistically specific terms (or so I believe). With this factored out, there are featural idiosyncracies located in demands made by specific lexical items, but this kind of idiosyncracy may be tolerable as it is segregated to the lexicon, a well known repository of eccentrics.[1]  At any rate, it is easy to see what would motivate a reconsideration of UG internal parameters.

The tractability problems related to parameter setting noted by Dresher-Fodor and company simply add to these motivations. 

That leaves us with the empirical arguments. These alone are what make parameter accounts worth endorsing, if they are well founded, and this is what is currently up for grabs and way beyond my pay grade. Cederic and Fritz Newmeyer (among others) have challenged the empirical validity of the key results. The most important discoveries amounted to the clumping of surface effects with the settings of single values, e.g. pro drop+subject inversion+no that-t effects together as a unit. Find one, you find them all.  However, this is what has been challenged. Is it really true that the groupings of phenomena under single parameter settings is correct?  Do these patterns coagulate as proposed? If not, and this I believe is Newmeyer’s point and strongly empahasized by Cedric, then it is not clear what parameters buy us.  Yes I-languages are different. So? Why think that this difference is due to different parameter settings? So, there is an empirical argument: are there data groupings of the kind earlier proposals advocated? Is the continuity thesis accurate and if so how does one explain this without parameters? These are the two big empirical questions and it is likely to be where the battle over parameters has been joined and, one hopes, will ultimately get resolved.

I’d like to epmpahsize that this is an empirical question.  If the data falls on the classical side then this is a problem for minimalists and exacerbates our task of addressing Darwin’s problem. So be it. Minimalism as I understand it has an empirical core and if it turns out that there is richer structure to UG than I would like, well tough cookies on me (and you if your sympathies tend in the same direction)!

Last point and I will end the rambling here. One nice feature of parameter models is the pretty metaphor it afforded for language acquisition as parameter setting. The switch box model is intuitive and easy to grasp. There is no equivalent for EM models and this is partly why nobody knew what to do with the damn thing.  EM never really got used to generate actual empirical research the way parameter setting models did, at least not in syntax. So can we envision a metaphor for non parameter setting models. I think we can. I offered one in A theory of syntax that I’d like to try and push it again here (I know that this is self aggrandizing, but tooting one’s own horn can be so much fun).  Here’s what I said there (chapter 7):

Assume for a moment that the idea of specified parameters is abandoned. What then?  One attractive property of the GB story was the picture that it came with.  The LAD was analogized to a machine with open switches.  Learning amounts to flipping the switches ‘on’ or ‘off’.  A specific grammar is then just a vector of these switches in one of the two positions.  Given this view there are at most 2^P grammars (P=number of parameters).  There is, in short, a finite amount of possible variation among grammars.

            We can replace this picture of acquisition with another one.  Say that FL provides the basic operations and conditions on their application (e.g. like minimality).  The acquisition process can now be seen as a curve fitting exercise using these given operations.  There is no upper bound on the ways that languages might differ though there are still some things that grammars cannot do.  A possible analogy for this conception of grammar is the variety of geometrical figures that can be drawn using a straight edge and compass.  There is no upper bound on the number of possible different figures.  However, there are many figures that cannot be drawn (e.g. there will be no triangles with 20 degree angles).  Similarly, languages may contain arbitrarily many different kinds of rules depending on the PLD they are trying to fit.

So think of the basic operations and conditions as the analogues of the straight edge and compass and think of language acquisition as fitting the data using these tools. Add to this a few general rules for figure fitting: add a functional category if required, pronounce a bottom copy of a chain rather than a top copy, add an escape hatch to a phase head. These are general procedures that can allow the LAD to escape the strictures of the limited operations a minimalistically stripped down FL makes available.  The analogy is not perfect. But the picture might be helpful in challenging the intuitive availability of the switch box metaphor.

That’s it. This post has also been way too long. Kudos to Neil and Cedric and the various very articulate commenters for making this such a fruitful topic for thought, at least for me. 

---

[1] Though I won’t discuss this now, it seems to me that the Cartographic Project and its discovery of what amounts to a universal base for all Gs is not so easily dismissed. The best hope is to see these substantive universals explicated in semantic terms, not something I am currently optimistic will soon appear.