JM:
Could we talk a bit more about the notion of simplicity and its development in your work? There's always been that notion of
theoretical simplicity; it's continued throughout all of your work. It's simply taken to be characteristic of the nature of scientific
investigation. Then there's also that internal simplicity which you pursued in
LSLT
[
The Logical Structure of Linguistic Theory]
and
Aspects
[
of the Theory of Syntax
]
. . .
[C]
NC:
. . . and also in the earlier work. That second one leads directly to what's called “
the Minimalist Program.” That's just another name for it. At some point – sort of like in the fifties when you begin to try to reframe the methodological studies of
language into a biological perspective – sometimes you can reframe the methodological conditions into empirical hypotheses about how organic systems, or maybe all systems, are formed. And to the extent that you can do that, you can investigate them as empirical hypotheses and look for evidence elsewhere – say, in the formation of snowflakes, or insect navigation, and so on – and see if there really are principles of computational complexity or whatever that are simply a part of nature, just as other natural laws are. And if you can reduce aspects of language to those, you have an account that – in the technical terminology of linguistics, where
explanatory adequacy is solving Plato's problem – goes beyond explanatory adequacy.[C] You can begin to ask why the principles of Universal Grammar have these forms and not other forms. It becomes an empirical problem of biology; and it's on a par with others – actually, the kind that Turing was interested in.
JM:
That's the third
factor
.
NC:
That's the third factor.
JM:
What about parameters? Are they in any way a development of that notion of internal simplicity?
NC:
In a certain sense. What actually happened – not in an instant, but if you look back, you can see what happened – was this. Look at
structural
linguistics, including [Zellig] Harris's work, which was essentially a set of procedures for reducing linguistic materials – a corpus – to some organized form. Harris, by the way, pursued [this project] with the same kind of
integrity that Goodman [discussed below] did – and it led to conclusions that seem to me incorrect for the same reasons. For him there was no truth of the matter: you could do it this way, you could do it that way, depends on which processes work. Those were essentially a set of procedures for reducing organized materials to a structural description of a particular type, and it was guided by some methodological considerations of simplicity, among others, such as utility. I spent a long time trying to work on the procedures, and finally convinced myself that they're not going to work, for fundamental reasons. You can see it at the most elementary level.
Let's rethink these issues in terms of language acquisition [for that leads to
parameters]. Harris wouldn't have, but it's a parallel question. Reducing a corpus, or organized materials, to a specific form is analogous to taking the data of experience and
ending up with an I-language; it's an analogous procedure, [but] the second one happens to be an empirical problem of biology, and that's preferable to the methodological problem of organizing material. The first step would have to be breaking up noises into small units – maybe syllables, maybe phonemes, or
whatever. The next step is going to have to be what
George Miller back in the fifties when he was thinking about these things called “chunking”; you have to have larger units. What's the next larger unit above, say, a phoneme or syllable? From the point of view of the organization of the structure of grammar, the next larger unit is morphemes. But that can't be,
because there cannot be a procedure to find morphemes. The reason is that a morpheme is a notion that is abstract in its relationship to data; something is a morpheme because of the way that it fits into a much broader system. So you're not going to be able to find them by some procedure. That's why Harris's approach to statistical analysis of sequences of elements to find morpheme boundaries just can't work; it can only work for units that are kind of like beads on a string – one occurs after another, and morphemes just aren't like that. It's more or less like that in English, but English is a morphologically impoverished language. Even in English it won't work, but in slightly morphologically richer languages [it's obvious that] it can't work at all. In fact, the next larger unit is going to be something that's sometimes called a phonological word – something that has integrated phonological properties and is more or less like a word, but it's not going to be what we think of as words, like if I say
whyd'ja leave
, “whyd'ja” is a phonological word, but it's a complicated thing from the point of view of its syntax and semantics. But that's the next biggest unit. Well, that was supposed to be a peripheral unit for structural linguistics, but it's going to be the
fundamental unit from a procedural point of view. If you want to get anything linguistically more significant, like a morpheme or a phrase, or a construction, or whatever, you're not going to be able to find it by these procedures. They break down right at the first step. That leads to the natural, but now I think erroneous, conclusion that what you're given by Universal Grammar, your genetic endowment, establishes a format: here's the kind of system that will count as a language. And then the task of the child – from another point of view, the
linguist – is to find the optimal instantiation of the format, given the data. That's where the simplicity measure comes in – what's optimal, by some measure – and then you have to spell out the measure. The measure would be all of the notations that people use – phrases, [
t]
becomes [
š
] preceding [
iyV
], and so on. These, as I always understood them – going way back to the fifties – are simply expressions of your internally set conception of
simplicity. They are ways of mapping a rule system into a form where you can assign a number, namely the number of symbols, and measure the simplicity numerically: ultimately, simplicity is going to be a numerical measure. So all of these are ways of assigning a number to a system of rules, and you hope that the method is going to capture authentic linguistic generalizations, and hence they'll really mean something – they'll be a part of the nature of language and your cognitive structure, and so on. So it is an empirical problem, but there's no computationally feasible method for going from data to finding the optimal instantiation of the format. That's why
Morphophonemics of Modern Hebrew
([Chomsky]
1951
/1979) gives a relative maximum. It says, “Well, let's pick this one and show that it's better than any slight modification of it.” But it's not really picking one from the data. That was in the forties; and it's inconceivable – it can't be done. It's computationally intractable. So it can't be the method of language acquisition; it can't be the truth about language.
Well, this framework – format, instantiation, simplicity measure, evaluation – that framework lasted pretty much through the seventies, and it did raise serious conceptual barriers to trying to find out what's
distinctive about language – what's the third factor, so that we can assign it to something else, and the residue will be what's distinctive about language. It's just a barrier: you could raise the question, and pursue it to an extent, but not too
much. That's where the principles and parameters approach was important; it separated the question of
language acquisition from the question of the format. Language acquisition under this point of view was a matter of setting the values of parameters, and the format for Universal Grammar no longer has to meet the condition that it is so restrictive and so highly articulated that it leads to a small number of choices only and therefore makes the computational task tractable. It could [now] turn out that Universal Grammar is very
unrestricted. If you have a format-instantiation framework, it's necessary that the format be
highly restricted and highly articulated, or you'll never be able to choose an instantiation, or pick one over another.
It's kind of like the projection problem [that Nelson Goodman discussed in his
Fact, Fiction, and Forecast
]: if you don't have any constraints, you're not going to be able to solve the projection problem. You're going to have to have very narrow constraints to have a feasible approach to picking an instantiation that's the right one – maybe not just one, but at least a small number. So throughout the whole format-instantiation-evaluation framework [period], it was necessary for the format to be highly restricted and highly articulated, with lots of special mechanisms, and so on and so forth – and therefore very little contribution of the third factor, and lots of highly specific components of language. It also made the problem of studying the evolution of language completely hopeless.
The principles and parameters approach broke that impasse by separating the problem of acquisition entirely from the problem: “What's the format?” It leaves all the questions open. But at least the conceptual barrier to studying the third factor is removed. It is then not impossible – and you can try to show that it is true – that the format for grammar actually does involve, to a high degree, principles of computational efficiency, and so on – which may be not only extra-linguistic, but extra-organic – and the acquisition problem is then shunted aside. It's a matter of fixing the parameters.
Of course, that raises another question, “Why does language have principles and parameters, and why these parameters?” That becomes another interesting empirical question which maybe you can answer on third factor grounds, and maybe not. In any case, [principles and parameters] made it possible to pursue in a much more serious way a search for factors like eliminating redundancy, simple rule systems, computational efficiency, and so on, on the basis of principles that may well be non-linguistic, not a part of Universal Grammar, and therefore not a part of the distinguishing characteristics of language. By the 1990s, a
number of people – I was one, but also Michael Brody, Sam Epstein, and others – felt that there had been enough progress in this approach that it was actually an identifiable research domain, and that's when the name [minimalism]
came along, just to identify that domain. It was a matter of picking up old problems and looking at them on the basis of new understandings, and plenty of assumptions – like the assumption that the principles and parameters approach is correct. There are plenty of posits there; no one can tell you what the parameters are. The closest that anyone has tried to get is Mark Baker's overview, which is very
interesting but, as many people have pointed out, does not get to what are often called “microparameters,” the kinds of things that Richard Kayne particularly has worked
on. They're very different. So what the whole picture of the array of parameters will look like is very much an open
question.
JM:
It's a complicated task disentangling all the various contributing factors, dealing with a child's course of development . . .
NC:
But [that's not at all an issue for most linguists]. Most linguists, and social scientists in general, are so data-oriented that they find it scandalous to accept [methodological] principles that really ought to be obvious – for example, the idea [see Chomsky
1986
and the introduction to Chomsky
1980
/2005] that you should try to study language acquisition in a pure case,
uncontaminated by the innumerable factors that actually enter – your parents speak one language, and the kids on the street speak another. That's obviously going to have all kinds of complicated effects on language acquisition. But if you really want to find the principles of language, you have to abstract away from that. That's why scientists do experiments. Galileo had to fight this battle, one that you would hope would have been over by now. Well, it's not over in his field. And the same thing is true over here [in linguistics]. So, for example, an awful lot of what is in any language – say, Arabic – is the result of
historical events that in themselves tell you nothing about the language faculty. Take the Norman
Conquest. The Norman Conquest had a huge effect on what became English. But it clearly had nothing to do with the evolution of language – which was all finished long before the Norman Conquest. So if you want to study the distinctive properties of language – what really makes it different from the digestive system – and some day maybe [study] the evolution of those properties, you're going to have to abstract away from the Norman Conquest. But that means abstracting away from the whole mass of data that interests the linguist who wants to work on a particular language. There's no contradiction in this; it's just a sane approach to trying to answer certain kinds of far-reaching questions about the nature of language. But that's often considered scandalous.
JM:
[Switching a bit,] what's your view now of the
status of
LSLT
? Is the work you've been doing recently a return to the project you find in
LSLT
? How do you see the historical relationship between that work and the Minimalist
Program?
NC:
It's different.
LSLT
was caught between many conflicting impulses. One was to do a distributional analysis, for methodological reasons, for some entity called “language,” whatever that is; and [that impulse] had in the back[ground] motivation[s] like reducing a corpus to a grammar. Another was the biological framework that was just beginning to be thought about. It was discussed in the Skinner review, which was about the same time – maybe a
little later – and in other works that were around.
LSLT
was sort of caught between them: now drop the first and turn to the second, and [try to] see what you're looking at.