Thursday, 23 December 2010

Defining Goals: Minimalist Angst (II)

[This is a draft excerpt from Chapter 2 of a proposed monograph on Vietnamese, in which I try to tackle some general theoretical problems. As ever, I really would appreciate comments, and will incorporate feedback in future drafts. Thank you. PS. If you wish to cite this, please reference it as  Duffield, Nigel Particles and Projections in Vietnamese Syntax, draft ms., University of Sheffield.

What is the goal of Linguistic Theory?

To begin, it is appropriate to consider how different linguists view the bigger picture: the overarching goals of grammatical theory. In a recent review article,[i] Cedric Boeckx, a leading advocate and practitioner of Mainstream Minimalism, responds to (frequently levied) criticisms that the framework is imprecisely formalized and hence inadequate for grammatical description, as follows:
…the goal of the generative enterprise in linguistic theory is not to decide whether natural languages can be studied in terms of sets, proofs or models. The idea expressed in Chomsky (1957) that it is possible to bifurcate the set of sentences into the grammatical and ungrammatical and define theoretical adequacy on the basis of that distinction was quickly abandoned.[ii] Instead, as is made extremely clear in the first chapter of Aspects of the Theory of Syntax (Chomsky 1965), the goal of linguistic theory, once firmly placed in a cognitive, and ultimately biological, setting, is to give an account of how children are able to acquire their native languages. In such a setting, talk of models, proofs or sets is largely irrelevant (Boeckx 2006, [emphasis mine]).
To anyone familiar—and in agreement—with Chomsky’s more general writing on linguistics over the past 30 years, this response may appear unexceptionable: it is certainly a predictable reiteration of the ‘party line’ on Explanatory Adequacy. Undeniably, these comments highlight the valid point that a scientifically interesting theory of language should have more ambitious goals than to provide a formally precise description of the grammatical structures of a particular language (even though this is a formidable—and some would claim, largely unanswered—challenge: see amongst others, Johnson & Lappin 1999, Seuren 2004, Blevins 2009). No-one could claim that the Chomskyan programme, from Aspects through GB to current Minimalism, has been short on ambition: there can be few more exciting or complex scientific projects than to understand the nature of the human language faculty or to explain children’s capacity to acquire their native language: what Pinker (1994: Chapter 1) terms ‘an instinct to acquire an art.’ 

Nevertheless, what is remarkable about the way in which the generative notion of Explanatory Adequacy has come to be defined, at least to sceptics of the generative enterprise—and especially to researchers involved in child language development—is the obvious disconnect between the rhetoric and stated rationale of mainstream generativism  on the one hand, and its empirical concerns, on the other. If “the goal of linguistic theory…is [in fact] to give an account of how children are able to acquire their native languages…” then the naïve observer might expect the core research agenda of Minimalism to be devoted to empirical issues in language acquisition research: for example, to determining what all children end up knowing about their language, and when they come to know it; to investigating the extent of true convergence on common grammatical principles (something that is assumed, but rarely tested); to explaining and reconciling the tension between the Logical Problem of Language Acquisition—how it is that children project beyond the variable input to which they exposed to achieve relatively uniform and highly sophisticated grammatical knowledge—and the Developmental Problem—giving an account of how and why children’s early comprehension and production diverges from that of adults (see Atkinson 1990, cf. O’Grady 1995); to understanding the relationship between grammatical knowledge and language processing in language development, and so forth. 

There are, of course, researchers both within and outside the generativist camp whose empirical work addresses precisely these kinds of questions: leading advocates of a generativist approach to language acquisition include Barbara Lust, Stephen Crain, Nina Hyams, Colin Philipps, Tom Roeper, William Snyder, Kenneth Wexler and their students and co-workers; significant alternative perspectives have been also offered by Elizabeth Bates, Melissa Bowerman, Eve Clark, Elena Lieven, William O’Grady, Mark Seidenberg, Dan Slobin and Michael Tomasello, amongst many others. However, the point is that acquisition research, far from driving developments in Minimalist theorizing, is usually regarded as (at best) being tangential to theoretical concerns.[iii] Perhaps the clearest indication of this neglect is the dearth of reference to (or use of) any empirical data from language acquisition in almost all of the core technical literature (e.g., Chomsky 1993, 1995, 1999, 2000, 2001, 2002): where acquisition data are advanced, it is generally only in the service of rhetorical theoretical arguments about the utility of negative evidence and/or Poverty of the Stimulus.

From one perspective, of course, this neglect is unsurprising: if one takes the innateness of language (I-language) to be a fact apriori, there is no logical reason to be concerned with the vagaries of E-language development. Moreover, it follows from innateness that there is little reason to investigate individual differences in development or grammar attainment (aside from pathological ones) nor, indeed, to be greatly concerned with cross-linguistic differences in language structure: from a Mainstream Minimalist perspective, innateness implies universality, hence surface structural differences are treated as peripheral to I-language, as “interface properties” at best, or as E-language properties.[iv] To draw on a frequently used analogy: if one is interested in understanding the genetic basis of avian flight, the developmental and cross-species differences between humming-birds, sparrows and eagles are probably of limited interest, fascinating though they may be to amateur birders, ethologists, or veterinary surgeons: see Marr (1982).[v]

Upon reflection though, there are significant difficulties with this line of argument. The of these is the obvious point that not everyone accepts claims of apriori Knowledge of Language (and the concomitant notion of instantaneous acquisition; see Chomsky 1975, Dresher 1999, cf. Weinberg 1990, Penner & Roeper 1998):[vi] even those, like myself, who are willing to entertain innateness as an hypothesis, generally prefer to use the theory to generate and test relevant empirical predictions against a representative sample of language data—for example, using syntactic theory to try to uncover contentful (see below) formal universals, or to probe the relationship between proposed parameters of grammatical variation and the steady-state grammars of particular languages, or, within the field of first language acquisition, to explore the independence of grammatical knowledge from uncontroversially learned properties of lexical knowledge (cf. Bates & Goodman 1987)—rather than to take innateness as a starting point for empirical inquiry.

A significant problem here is that the standard characterization of explanatory adequacy conflates two quite separate research questions, viz. (i), determining the nature of the human language faculty (FL), and (ii), explaining children’s capacity to acquire their native languages (instances of L). Though these are intimately related—and though it may be reasonable to suppose under a particular presentation of the argument that understanding the first question is prerequisite for progress with the second—the issues are logically and empirically separable.[vii] This is clearly demonstrated by the fact that it is possible to hold contrary positions with respect to the innateness of the two capacities—indeed, for there to be distinct empirical ‘facts of the matter’. For example, it may turn out that Knowledge of Language is part of our biological endowment, but that the capacity to deploy this knowledge to acquire a particular grammar is not—or rather, is not domain-specific, as generative theory generally insists: see e.g., Anderson & Lightfoot (2002). Alternatively, it could be that the capacity to acquire language is innately given and domain-specific,[viii] but that the steady-state grammatical systems that are actually acquired (LEnglish, Lfrench, Lchichewa, etc.) are externally determined, internalized theories of linguistic behavior, which are partly—or even largely—unconstrained by biological or domain-specific cognitive factors. Indeed, Chomsky (1975) considers such an idea quite plausible:
I have been assuming that UG suffices to determine particular grammars (where again, a grammar is a system of rules and principles that generates an infinite class of sentences with their formal and semantic properties). But this might not be the case. It is a coherent and perhaps correct proposal that the language faculty constructs a grammar only in conjunction with other faculties of mind. If so, the language faculty itself provides only an abstract framework, an idealization that does not suffice to determine a grammar (Chomsky 1975: 41) [emphasis mine: NGD].
This latter conception of grammar acquisition is one to which many might subscribe, even beyond the generativist camp. It will also be clear that these two options do not exhaust the possibilities; many other conceptions are possible. Whatever the truth of the matter however, these are logically distinct research questions; hence, it is distracting to use one as the rationale for the other, as most mainstream generative syntacticians seem to have done recently, including Boeckx.[ix]



[i] Review of Postal (2003) Sceptical Linguistic Essays. Oxford: OUP. For a more positive assessment of Boeckx’ commentary, see Collins (2009).
[ii] Boeckx accurately represents Chomsky’s assertion that the basis of grammatical well-formedness of sentences is not the object of inquiry, something that is explicit in the following quote:
The class [of well-formed (grammatical) expressions of L] has no significance. The concepts ‘well-formed’ and ‘grammatical’ remain without characterization or known empirical justification; they played virtually no role in early work on generative grammar except in informal exposition, or since (Chomsky 1993: 44-45).
Several authors have questioned whether this remark—the last clause especially—has any basis in fact. As Geoff Pullum observes, uncompromisingly:
The concept of grammaticality not only played a role in early generative grammar, but the role it played was that of being the only data considered relevant in linguistics…the claim that the concept of grammaticality played no role in early generative grammar is certainly an untruth (Pullum 2006: 139 [Emphasis mine]).
In fact, both quotations contain independently valid statements.  Pullum is surely correct to say that the concept of grammaticality has always played a crucial role in generative theory construction and practice, from Aspects to the present day (however poorly the notion may be understood (Chomsky 1977, Allen & Seidenberg 1999). At the same time, Chomsky’s (and Boeckx’s) assertion is correct—in a very narrow, almost legalistic, sense—to the extent that grammaticality is taken to refer to classes or extensional sets of well-formed vs. ill-formed sentences: at least since Chomsky (1981), it has been clear that such sets of sentences belong to ‘E-language’, which Chomsky rejects as a legitimate, or even coherent, object of inquiry. Nevertheless, what is important is the set of mental states (Knowledge of Language) that occasions grammaticality, or rather, underlies the capacity to give “grammaticality judgments” about core data: it seems perverse to deny that this capacity has always been central to generative theorizing or practice (or indeed that to think that it should not be).
[iii] (It should be) needless to say that there is nothing original about this observation: since the beginning of generative theory, not only psycholinguistics, psychologists and developmentalists and typologists, but also dissenting voices within the generativist camp have repeatedly criticized the failure to incorporate—or even acknowledge—the results of empirical investigations of grammatical phenomena from other sources: see Eysenck (1984), Cutler (2005), or the following well-known quote from Tom Roeper, cited in Newmeyer (1983), Featherston (2007):
‘when psychological evidence has failed to conform to linguistic theory, psychologists have concluded that linguistic theory was wrong, while linguists have concluded that psychological theory was irrelevant (Roeper 1982).’
[iv] As discussed below, the change from GB to Minimalism marks a significant change in imperviousness of core syntax to external language-particular factors, including word order.
[v] From this perspective, one might as well conclude that penguins and chickens ‘know’ how to fly (“I-flight”), or that whales know how to walk (“I-walk”), even though subsequent evolutionary changes have left them unable to implement this knowledge (“E-locomotion”).  Though such a conclusion may seem absurd to many, it is a logically consistent and rational one, reflecting an attitude that is, I think, not so distant from many syntacticians’ views on grammatical competence.
[vi] For example, Dresher (1999) writes: 
‘The early stages of acquisition, during which the grammars of language learners are most idiosyncratic and most different from the target adult language, have no effect upon the grammar eventually acquired. As far as the final result goes, these stages can be ignored for purposes of the logical problem of language acquisition, and acquisition is as if it were instantaneous.’
Contrast this with Weinberg (1990: 165): 
As is well known, current work in generative grammar makes the major idealization of instantaneous acquisition, the assumption that there is no ordering relationship between pieces of linguistic knowledge. This assumption is assuredly false.’ See Ayoun (2005) for alternative discussion.
[vii] Not everyone accepts this logical priority, of course: see, for example, Seidenberg & MacDonald (1999): 
Instead of asking how the child acquires competence grammar, we view acquisition in terms of how the child converges on adult-like performance in comprehending and producing utterances. This performance orientation changes the picture considerably with respect to classic issues about language learnability, and provides a unified approach to studying acquisition and processing (Seidenberg & MacDonald 1999: 570).
[viii] A capacity variously labeled Language Acquisition Device (LAD), the “language organ”, Faculty of Language (FL) etc.: see below.
[ix] To use a social science analogy, to claim that the goal of linguistic theory is to explain child language acquisition is not unlike claiming that the goal of economic theory is to explain the poverty gap in capitalist societies: whether intentional or not, the rhetorical significance of referencing a vulnerable social group (young children, the poor, respectively) should not be underestimated.

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