I have avoided writing this post for the last three weeks. I really didn’t want to do it and still really don’t want to do it. The reason is that I have reluctantly concluded that the position that I am going to discuss is silly. This position is a critique of the mentalist vision of Generative Grammar, the one that Chomsky has been sedulously developing over the last 50 years. It flies under the flag of Platonism and its current most vigorous exponent is Paul Postal. Nonetheless, the argument, to the degree that I understand it, and sadly I think that I do, is very poor. It lays not a glove on its Chomskian bête noir and were its advocates less vociferous I would have left it to die in the obscurity that it deserves. However, given the play that this position has received in the discussion threads it deserves some attention.
Before proceeding, some caveats.
First, Paul Postal is, in my view, an excellent syntactician. I wish that I had made even a tenth of the contributions to syntax that he has made. Were I to follow my own advice (here), this would mean that I would think very hard before attributing to him a silly position. I will outline what I take the view to be below and I apologize in advance if I got it wrong. But I really don’t think I did as he has been very careful in laying it out. However, I want to make it clear that though I find the argument silly, I consider Postal himself to be an extremely talented and interesting linguist.
Second, I will not be attacking Platonism here, at least no much (well a little, at the end). In other words, my main concern is to examine the claim that the Chomsky position is incoherent, a claim that Postal and others (Hi C!) have repeatedly made. I will not be extensively discussing the virtues or vices of a Platonist conception. I actually have little sympathy for this understanding of the project, but, hey, whatever floats your boat. My aim is not to convert the heathens, but to defend the realm. Incoherence is a nasty vice. Were the biolinguistic-mentalist interpretation of linguistics truly incoherent this would be a serious problem. My only aim is to show that there is currently no argument that I can see in support of this conclusion. Assertions, yes. Arguments, no.
Last point: I will concentrate entirely on one text, Paul’s Remarks on the foundations of linguistics (here). I concentrate on this because it was aimed at a philosophical audience and is a concise version of the argument. If there are other better arguments elsewhere, then I am sure that partisans of the truth will be happy to reproduce them in the comments section for us to examine. I encourage you to do so if you feel there is a better argument out there. But please don’t simply refer to the existence of the arguments, actually give them. Produce the arguments. Then we can see if they are better than the one that I deliver below. Ok enough (cowardly) prologue.
The argument is actually very simple. It claims that the mentalist perspective rests on a confusion between Natural Language (NL) and knowledge of NL. More elaborately
1. A field is about the objects it studies
2. Linguistics is about Natural Language (NL)
3. Knowledge of NL is not NL
4. Mentalism identifies the two.
5. As a result, the mentalist conception of linguistics leads to incoherence
Here is another version, a reduction:
6. Say that there is knowledge of NL
7. Therefore, there is NL
8. Therfore, for any specific NL, knowledge of that NL is distinct from that NL
What’s the basis of the inference from (6) to (7) and (8)? It’s a consequence of the “general features of the knowledge relation, regardless of how ultimately analyzed.” In particular, “for any X, knowledge of X can only exist if X has existed or does exist. Consequently, the assumption shared by both foundational positions [Platonism and Mentalism/NH] under discussion that there is knowledge of NL entails that there is NL” (235). As Postal emphasizes, the key critical observation is that the ‘knowledge-of’ or ‘know’ is a two-place predicate/relation. From this it follows that NL is distinct from knowledge of NL and so any attempt to analyze NLs as mental states must lead to incoherence.
That’s the argument. So far as I can tell, in its entirety. It rests on an analysis of the word ‘knowledge’ as a relational predicate and concludes that any identification of NL in terms of mental states must be incoherent.
Now, Postal is quite aware that Chomsky has rejected this analysis. He quotes Chomsky liberally as noting that he does not believe that language has an “objective existence apart from its mental representations” (235, note 5 quoting from Language and Mind). However, he will have none of this. Why? Because ‘knowledge’ is a two place relation and that’s that.
To belabor the point, let’s see why this is such a poor argument. First, whatever the “logic” of the term ‘knowledge’ there is nothing incoherent in proposing that in the domain of linguistics we are going to reject the relational reading of the term. It is perfectly coherent to suppose that when the object of know is NL then the predicate should be treated as one-place not 2. This would treat knowledge of NL like taking a bath, or having a headache/hallucination, weighing 10 lbs, having three dimensions. To say that Sam has a headache is not to postulate a relation between Sam and some headache. It is to ascribe to him a certain unpleasant mental state. Similarly with taking a bath (aka, bathing) and weighing 10 lbs or having 3 dimensions (aka, being 3 dimensional). These look transitive grammatically, but they quite plausibly denote properties. Chomsky’s proposal is (and has been) that the same holds for locutions like knows French/English etc.
First note, that if this is conceded, then the arguments above disintegrate. Indeed, if you allow this move, then there is nothing incoherent about analyzing knowledge of language as having/being in a certain mental state. On this well known view, knowing English is one state, knowing French another etc. UG will be the study of these possible states and how they arise in the minds/brains of their possessors. We can ask how these states enter into processing and production, how brains instantiate these states etc. All the stuff that Chomsky and Co. have been saying forever turn out to be perfectly coherent, indeed anodyne.
Now one might object that this is not kosher, you can’t just analyze terms any way you want. ‘Knowledge-of’ is a relational term so treating it as a property denoting expression in this context is illicit. But, that’s just wrong. Chomsky is providing a conception of a scientific project. In so doing, he is free to modify ordinary locutions as he sees fit in service of advancing the specific investigations at hand. In other words, the aim here is not to provide an ordinary language analysis of know but to provide methodological underpinning for a practice. Chomsky’s proposal is that we understand know NL as ascribing a property of a person. In virtue of having that property that person is endowed with certain capacities. Indeed, having that property, being in the specified state, is how he proposes to analyze linguistic capacity (aka, competence). Being in a certain mental state endows me with the capacity to speak my idiolect. Being human endows me with the capacity to acquire linguistic states when put in the right environmental circumstances. None of this is mysterious. It may be wrong (NOT!!) but it is not close to being incoherent. Or, more relevantly, observing that in ordinary language know is a 2-place predicate is entirely beside the point.
Virtually all the other critiques offered rest on this one. Postal provides an analysis of NL as an infinite collection of sentences and then lambastes Chomsky for not being able to provide a coherent understanding of NL sentences given his mentalism. Why? Because there are an infinite number of sentences but mental organs are bounded in both space and time and so cannot “be placed in one to one correspondence with infinitely many things (244).” Of course, there is nothing odd about mental states embodying finitely specifiable recursive procedures that can characterize the properties of an unbounded number of sentences. Indeed, the whole idea from the get go has been that knowledge of G amounts to embodying a finite specification of such recursive rules. Postal is, or course, right, that in practice these mental states will never be used to produce or understand more than a fraction of those tokens that it could produce or understand. But this is just to say that we have an open ended grammatical potential, one bounded in various ways by the physical properties of the machine that embodies those states. None of this is mysterious. We have perfectly good models of how machines can embody recursive procedures whose application is limited by size of memory, CPU, energy allocations etc. None of this is opaque and none leads to incoherence. Chomsky has been very careful to emphasize the three I-s: intentional, individual, internal. It is commonplace to finitely specify an infinite set of objects. Chomsky’s rejection of sentences as sets is not a serious problem.
There is more, but none of it is enlightening in my view. Before quitting let me cast a few beady eyes on the Platonist alternative that Postal endorses. It may not be incoherent, but to me it is deeply unattractive. Here are three quick reasons why I find it of dubious interest.
First, though Postal insists that he has nothing against the study of knowledge of language, he does want to insist that linguistics proper is a purely formal study not subject to the whims of empirical work. As I mentioned in the last post, I find this position to be counterproductive. The aim should be to expose yourself to the greatest empirical buffeting. Hiding one’s favorite views in a formal cloister insulated from potential contact with other kinds of scary facts cannot help but breed a kind of unfortunate intellectual insularity.
Second, the Platonist conception leaves it entirely unclear how one is supposed to bring the study of NL into contact with the study of knowledge of NL. Sentences are abstract, have “no locus in time or space” and “can cause no reactions” nor “itself be caused by anything” (239). If so, it remains a mystery of how it can be known. By insisting on the great gulf between what linguistics on this view studies and what can be studied empirically, we are left with no idea why it is that linguistics should concern anyone with cognitive interests. Of course, these Platonist views can be modulated. Plato himself had a Platonist program quite congenial to mentalist investigation precisely because he grounded the perception of forms in pre-existing innate knowledge. But, on this view, studying the mental could be a way of studying the forms. Moreover, for Plato physical particulars were reflections of the forms, albeit distorted ones (remember the cave analogy). In other words, Plato went out of his way to attenuate the ontological distance between his forms and the empirical and mental world. Postal goes out of his way to emphasize the great divide and so leaves it entirely unclear why anyone interested in mentalist or biolinguistic sorts of concerns should care about what he is working on. As it turns out, Postal’s metaphysical sympathies don’t really affect his linguistic conclusions and so as a consumer I can happily understand his interesting syntactic proposals and use them as I see fit. In other words, I can ignore the Platonism as it is effectively idle.
Third, the idea that the practice of linguistics looks like anything done in a math department is heroic. Most of what linguists do is go around asking other native speakers for judgments. Last I checked this is not the practice of working mathematicians. Recall the joke: Linguist doing number theory: Thesis: All odd numbers are prime. 3 is prime, 5 is prime, 7 is prime, 9 is prime. Hmm 9 is prime?, Can you get 9 as a prime? I think I can. From where I sit, the practice of syntax has virtually no resemblance to what takes place in math departments. We truck in analyses, they in proofs. We do some “modeling,” and describe empirical phenomena in semi formal ways, but to take this as serious math, well, I would advise against submitting this to JAMA.
Forth, if one is a serious Platonist about NL then the following becomes a serious option: normal native speakers of an NL may not know their own NL. As Postal has correctly noted, a native speaker is exposed to at most a miniscule subset of the linguistic objects of an NL. And given that we don’t identify an NL with a mental state of a native speaker, there is no reason to think that native speakers in general do know their NLs. I find this view to be, ahem, odd. If native speakers don’t know their own NL then nobody knows anything. But for a Platonist the fact that many/most/all native speakers know their NL in virtue of being competent speakers of their NLs should be a bit of a surprise.
None of this implies that Platonism is “incoherent.” In matters methodological I am a pluralist. Postal is not similarly catholic. He has claimed that Chomskyan mentalism is incoherent. From what I can tell, he is just plain wrong.
I will end here. I cannot recommend that you take the time to read Postal’s Platonic disquisitions. I learned little of interest from the one paper I read. Moreover, the reading was deeply unpleasant. Postal is clearly a very angry man. His discussions are crude and, in my view, deeply offensive. I believe that he should apologize for the way that he has conducted himself. He has proven to me that Chomsky is actually a nicer man than I already believed he was. Only that explains why he has refrained from addressing such weak arguments made with so little decorum.
 There has been some discussion of apparent problems in the threads to the Fodor posts. Christine has mooted several and Avery, Andy and Jan have delivered significant push back. To my mind, they have easily gotten the better of the discussion, but that is for you to judge.
 It’s instructive to contrast this with mathematical knowledge, which is indeed opaque to most humans.