Friday, January 13, 2017

No time but...

It's file reading season so my time is limited right now. That and the hangover from the holidays has made me slower. Nonetheless, I thought that I would post this very short piece that I read on computational models in chemistry (thx to Bill Idsardi for sending it my way). The report is interesting to linguists, IMO, for several reasons.

First, it shows how a mature science deals with complexity. It appears to be virtually impossible to do a full theoretically rigorous computation given the complexity of the problem, "but for the simplest atoms." Consequently, chemists have developed approximation techniques (algorithms/functions) to figure out how electrons arrange themselves in "bulk materials." These techniques are an artful combination of theory and empirical parameter estimation and they are important precisely because one cannot compute exact results for these kinds of complex cases. This is so even though the relevant theory is quite well known.

I suspect that if and when linguists understand more and more about the relevant computations involved in language we will face a similar problem. Even were we to know everything about the underlying competence and the relevant mental/brain machinery that uses this knowledge, I would expect the interaction effects among the various (many) interacting components to be very complex. This will lead to apparent empirical failure. But, and this is the important point, this is to be expected even if the theory is completely correct. This is well understood in the real sciences. My impression is that this bit of wisdom is still considered way out there in the mental sciences.

Second, the discussed paper warns against thinking that rich empirics can substitute for our lack of understanding. What the reported paper does is test algorithms by seeing how they perform in the simple cases where exact solutions can be computed. How well do those techniques we apply in sophisticated cases work in the simple ones? The questions: How well "different...algorithms approximated the relatively exact solutions."

The discovery was surprising: After a certain point, more sophisticated algorithms started doing worse at estimating the geometry of electrons (this is what one needs to figure out a material's chemical properties). More interesting still, the problem was most acute for "algorithms based on empirical data." Here's the relevant quote:

Rather than calculating everything based on physical principles, algorithms can replace some of the calculations with values or simple functions based on measurements of real systems (an approach called parameterization). The reliance on this approach, however, seems to do bad things to the electron density values it produces. "Functionals constructed with little or no empiricism," the authors write, "tend to produce more accurate electron densities than highly empirical ones."

It seems that when "we have no idea what the function is" that throwing data at the problem can make things worse. This should not be surprising. Data cannot substitute for theoretical insight. Sadly, this trivial observation is worth mentioning given he spirit of the age.

Here is one possible implication for theoretical work in linguistics: we often believe that one tests a theory best by seeing how it generalizes beyond the simple cases that motivate it. But in testing a theory in a complex case (where we know less) we necessarily must make assumptions based less on theory and more on the empirical details of the case at hand. This is not a bad thing to do. But it carries its own risks, as this case illustrates. The problem with complex cases is that they likely provoke interaction effects. To domesticate these effects we make useful ad hoc assumptions. But doing this makes the fundamental principles more opaque in the particular circumstance. Not always, but often.

Friday, January 6, 2017

Where Norbert gets pounded for his biological ignorance

I recently co-wrote a comment (see here) on a piece by Berlinski and Uriagereka on Vergnaud's theory of case (see here and here), of which I am a fan, much to one of my colleagues continual dismay. The replies were interesting, especially the one by Berlinski. He excoriated the Jacobian position I tried to defend. His rebuttal should warm the hearts of many who took me to task for my thinking that it was legit to study FL/UG without doing much cross G inquiry.  He argues (and he knows more about this than I do) that the Jacob idea that the same fundamental bio mechanisms extend from bacteria to butterflies is little more than myth. The rest of his comment is worth reading too for it rightly points out that the bio-ling perspective is, to date, more perspective and less biology.

Reaction? Well, I really like the reply's vigorous pushback. However, I don't agree. In fact, I think that what he admires about Vergnaud's effort is precisely what makes the study of UG in a single language so productive.  Here's what I mean.

Vergnaud's theory aimed to rationalize facts about the distribution of nominals in a very case weak language (viz. English). It did this elegantly and without much surface morphology to back it up. Interestingly, as readers of FoL have noted, the cross G morpho evidence is actually quite messy and would not obviously support Vergnaud's thesis (though I am still skeptical that it fails here). So, the argument style that Vergnaud used and that Berlinski really admires supports the idea that intensive study of the properties of a single G is a legit way to study the general properties of FL/UG. In fact, it suggests that precisely because this method of study brackets overt surface features it cannot be driven by the distributions of these features which is what much cross G inquiry studies.  Given this logic, intensive study of a single G, especially if it sets aside surface reflexes, should generalize. And GG has, IMO, demonstrated that this logic is largely correct.  So, many of the basic features of UG, though discovered studying a small number of languages have generalized quite well cross linguistically. There have, of course, been modifications and changes. But, overall, I think that the basic story has remained the same. And I suspect that not a few biologists would make the same point about their inquiries. If results from model systems did not largely generalize then they would be of little use. Again, maybe they aren't, but this is not my impression.

Ok, take a look at Berlinski's comments. And if you like this, take a look at his, IMO, most readable book Black Mischief.

Inchoate minimalism

Chomsky often claims that the conceptual underpinnings of the Minimalist Program (MP) are little more than the injunction to do good science. On this view the eponymous 1995 book did not break new ground, or announce a new “program” or suggest foregrounding new questions. In fact, on this view, calling a paper A Minimalist Program for Linguistic Theory was not really a call to novelty but a gentle reminder that we have all been minimalists all along and that we should continue doing exactly what we had been doing so well to that point. This way of putting things is (somewhat) exaggerated. However, versions thereof are currently a standard trope, and though I don’t buy it, I recently found a great quote in Language and Mind (L&M) that sort of supports this vision.[1] Sorta, kinda but not quite.  Here’s the quote (L&M:182):

I would, naturally, assume that there is some more general basis in human mental structure for the fact (if it is a fact) that languages have transformational grammars; one of the primary scientific reasons for studying language is that this study may provide some insight into general properties of mind. Given those specific properties, we may then be able to show that transformational grammars are “natural.” This would constitute real progress, since it would now enable us to raise the problem of innate conditions on acquisition of knowledge and belief in a more general framework….

This quote is pedagogical in several ways. First, it does indicate that at least in Chomsky’s mind, GG from the get-go had what we could now identify as minimalist ambitions. The goal as stated in L&M is not only to describe the underlying capacities that make humans linguistically facile, but to also understand how these capacities reflect the “general properties of mind.” Furthermore, L&M moots the idea that understanding how language competence fits in with our mental architecture more generally might allow us to demonstrate that “transformational grammar is “natural”.” How so? Well in the obviously intended sense that a mind with the cognitive powers we have would have a faculty of language in which the particular Gs we have would embody a transformational component. As L&M rightly points out, being able to show this would “constitute real progress.” Yes it would.

It is worth noting that the contemporary conception of Merge as combining both structure building and movement in the “simplest” recursive rule is an attempt to make good on this somewhat foggy suggestion. If by ‘transformations’ we intend movement, then showing how a simple conception of recursion comes with a built in operation of displacement goes some distance in redeeming the idea that transformational Gs are “natural.”[2]

Note several other points: The L&M quote urges a specific research strategy: if you are interested in general principles of cognition then it is best to start the investigation from the bottom up. So even if one’s interest is in cognition in general (and this is clearly the L&M program) then right direction of investigation is not from, e.g. some a priori conception of learning to language but from a detailed investigation of language to the implications of these details for human mental structure more generally. This, of course, echoes Chomsky’s excellent critiques of Empiricism and its clearly incorrect and/or vacuous conceptions of reinforcement learning. 

However, the point is more general I believe. Even if one is not Empiricistically inclined (as no right thinking person should be) the idea that a body of local doctrine concerning a specific mental capacity is an excellent first step into probing possibly more general capacities seems like excellent method. After all, it worked well in the “real” sciences (e.g. Galileo’s, Copernicus’ and Kepler’s laws were useful stepping stones to Newton’s synthesis) so why not adopt a similar strategy in investigating the mind/brain? One of GGs lasting contributions to intellectual life was to demonstrate how little we reflexively know about the structure of our mental capacities. Being gifted linguistically does not imply that we know anything about how our mind/brain operates. As Chomsky likes to say, being puzzled about the obvious is where thinking really begins and perhaps GG’s greatest contribution has been to make clear how complex our linguistic capacities are and how little we understand about its operating principles.

So is the Minimalist Program just more of the same, with nothing really novel here? Again, I think that the quote above shows that it is not. L&M clearly envisioned a future where it would be useful to ask how linguistic competence fits into cognition more broadly. However, it also recognized that asking such “how” questions was extremely premature. There is a tide in the affairs of inquiry and some questions at some times are not worth asking. To use a Chomsky distinction, some questions raise problems and some point to mysteries. The latter are premature and one aim of research is to move questions from the second obscure mystical column to the first tractable one. This is what happened in syntax around 1995; the more or less rhetorical question Chomsky broached in L&M in the late 60s became a plausible topic for serious research in the mid 1990s! Thus, though there is a sense in which minimalism was old hat, there is a more important sense in which it was entirely new, not as regards general methodological concerns (one always values simplicity, conciseness, naturalness etc) but in being able to ask the question that L&M first posed fancifully in a non-trivial way: how does/might FL fit together with cognition more generally?

So what happened between 1968 and 1995? Well, we learned a lot about the properties of human Gs and had plausible candidate principles of UG (see here for some discussion). In other words, again to use Chomsky’s framing (following the chemist Davy), syntax developed a “body of doctrine” and with this it became possible to use this body of doctrine to probe the more general question. And that’s what the Minimalist Program is about. That’s what’s new. Given some understanding of what’s in FL we can ask how it relates to cognition (and computation) more generally. That’s why asking minimalist questions now is valuable while asking them in 1967 would have been idle.

As you all know, there is a way of framing the minimalist questions in a particularly provocative way, one that fires the imagination in useful ways: How could this kind of FL with these kinds of principles have evolved? On the standard assumption (though not uncontroversial, see here on the “phenotypic gambit”) that complexity and evolvability are adversarial, the injunction to simplify FL by reducing its linguistically proprietary features becomes the prime minimalist project. Of course, all this is potentially fecund to the degree that there is something to simplify (i.e. some substantive proposals concerning what the operative FL/UG principles are) and targets for simplification became worthwhile targets in the early 1990s.[3] Hence the timing of the emergence of MP.

Let me end by ridding off on an old hobbyhorse: Minimalism does not aim to be a successor to earlier GB accounts (and its cousins LFG, HPSG etc). Rather MP’s goal is  to be a theory of possible FL/UGs. It starts from the assumption that the principles of UG articulated from 1955-1990s are roughly correct, albeit not fundamental. They must be derived from more general mental principles/operations (to fulfill the L&M hope). MP is possible because there is reason to think that GB got things roughly right. I actually do think that this is correct. Others might not. But it is only once there is such a body of FL/UG doctrine that MP projects will not be hopelessly premature. As the L&M quote indicates, MP like ambitions have been with us for a long time, but only recently has it been rational to hope that they would not be idle.

[1] Btw, L&M is a great read and those of you who have never dipped in (and I am looking at anyone under 40 here) should go out and read it.
[2] And if we go further and assume that all non-local dependencies are mediated by ((c)overt) movement then all variety of transformations are the product of the same basic “natural” process. Shameless plug: this is what this suggests we do.
[3] Why then? Because by then we had good reasons for thinking that something like GB conception of UG was empirically and theoretically well-grounded. See here (and four following entries) for discussion.

Tuesday, December 20, 2016

talking brains

In a recent paper (here), Tecumseh Fitch (TF) and colleagues argue that monkey vocal tracts are structurally adequate for the production of human speech sounds. Why is this important? Because, as the paper puts it:

Our findings imply that the evolution of human speech capabilities required neural changes rather than modifications of vocal anatomy. Macaques have a speech-ready vocal tract but lack a speech-ready brain to control it.

This, in other words, puts another nail in the coffin of those that look to provide a continuity thesis style of explanation of human linguistic facility based on a quantitative extension of what appears in our nearest cousins (i.e. If this is right it then Phil Lieberman was wrong). If TF is right, then all that effort expended in trying to teach primates to speak was a waste of time (which it was) and the failure was not one that could be resolved by teaching them sign (which in fact didn’t help) because the problem was neural not vocal. IMO, the futility of this line of inquiry has been pretty obvious for a very long time, but it is always nice to have another nail in a zombie’s coffin.

The results are interesting for one other reason. It suggests that Chomsky’s assumption that externalization is a late add-on to linguistic competence is on the right track. FT provides evidence that vocalization of the kind that humans have is already in place engineering wise in macaques. Their vocal tracts have the wherewithal to produce a range of vowels and consonants similar to those found in natural language. If they don’t use this to produce words and sentences (or movie reviews or poems) it is not because they lack the vocal tract structure to do so. What they lack is something else, something akin to FL. And this is precisely Chomsky’s suggestion. Whatever changed later coupled with an available system of externalization. This coupling of the new biologically unique system with the old biologically speaking more generally available system was bound to be messy given they were not made for each other. Getting the two to fit together required gerrymandering and thus was born (that messy mongrel) morpho-phonology. FT supports this picture in broad outlines.

One more point: if externalization follows the emergence of FL, then communication cannot be the causal root of FL. Clearly, whatever happened to allow FL to emerge came to take advantage of an in-place system capable of exploitation for verbal communication. But it seems that these capacities stayed fallow language wise until the “miracle” that allowed FL to emerge obtained. On the assumption that coupling FL with an externalization mechanism took time, then the selective pressure that kept the “miracle” from being swept away cannot have been communicative enhancement (or at least not verbal communicative enhancement). This means that Chomsky-Jacob suggestion (here) that the emergence of FL allowed for the enhancement of thought and that is what endowed it with evolutionary advantage is also on the right track.

All in all, not a bad set of results for MP types.

Tuesday, December 13, 2016

Domesticating parameters

I have a confession to make: I am not a fan of parameters. I have come to dislike them for two reasons. First, they don’t fit well with what I take to be Minimalist Program (MP) commitments. Second, it appears that the evidence that they exist is relatively weak (see here and here for some discussion). Let me say a bit more about each point.

First the fit with MP: as Chomsky has rightly emphasized, the more we pack into UG (the linguistically proprietary features of FL) the harder it is to solve Darwin’s Problem in the domain of language. This is a quasi-logical point, and not really debatable. So, all things being equal we would like to minimize the linguistically specific content of FL. Parameters are poster children of this sort of linguistically specific information. So, any conception of FL that comes with a FL specified set of ways that Gs can differ (i.e. a specification of the degrees of possible options) comes at an MP cost. This means that the burden of proof for postulating FL internal parameters is heavy and should be resisted unless faced with overwhelming evidence that we need them.[1]

This brings us to the second point: it appears that the evidence for such FL internal parameters is weak (or so my informants tell me (when do fieldwork among variationists)). The classical evidence for parameters comes from the observation that Gs differ wholesale not just retail. What I mean by this is that surface changes come in large units. The classic example is Rizzi’s elegant proposal linking the fixed subject constraint, pro-drop and subject inversion. What made these proposals more than a little intriguing is that they reduced what looked like very diverse G phenomena to a single source that further appeared to be fixable on the basis of degree-0 PLD. This made circumscribing macro-variation via parameters very empirically enticing.  The problem was that the proposals that linked together the variation in terms of single parameter setting differences proved to be empirically problematic.

What was the main problem? It appears that we were able to find Gs that dissociated each of the relevant factors. So we could get absence of fixed subject condition effects without subject inversion or pro-drop.  And we could find pro-drop without subject inversion. And this was puzzling if these surface differences all reflect the setting of a single parameter value.

I used to be very moved by these considerations but a recent little paper on domestication has started me rethinking whether there may not be a better argument for parameters, one that focuses less on synchronic facts about how Gs differ and more on how Gs change over time. Let me lay out what I have in mind, but first I want to take a short detour into the biology of domestication because what follows was prompted by an article on animal domestication (here).

This article illustrates the close conceptual ties between modern P&P theories and biology/genetics. This connection is old news and leaders in both fields have noted the links repeatedly over the years (think Jacob, Chomsky).  What is interesting for present purposes is how domestication has the contours of a classic parameter setting story.

It seems that Darwin was the first to note that domestication often resulted in changes not specifically selected for by the breeder (2):

Darwin noticed that, when it came to mammals, virtually all domesticated species shared a bundle of characteristics that their wild ancestors lacked. These included traits you might expect, such as tameness and increased sociability, but also a number of more surprising ones, such as smaller teeth, floppy ears, variable colour, shortened faces and limbs, curly tails, smaller brains, and extended juvenile behaviour. Darwin thought these features might have something to do with the hybridisation of different breeds or the better diet and gentler ‘conditions of living’ for tame animals – but he couldn’t explain how these processes would produce such a broad spectrum of attributes across so many different species.

So, we choose for tameness and we get floppy ears.  Darwin’s observation was strongly confirmed many years later by a dissident Soviet biologist Dimitri Belyaev. Belyaev  domesticated silver foxes. More specifically (5):

He selected his foxes based on a single trait: tameness, which he measured by their capacity to tolerate human proximity without fear or aggression. Only 5 per cent of the tamest males and 20 per cent of the tamest females were allowed to breed.

Within a few generations, Belyaev started noticing some odd things. After six generations, the foxes began to wag their tails for their caretakers. After 10, they would lick their faces. They were starting to act like puppies. Their appearance was also changing. Their ears grew more floppy. Their tails became curly. Their fur went from silver to mottled brown. Some foxes developed a white blaze. Their snouts got shorter and their faces became broader. Their breeding season lengthened. These pet foxes could also read human intentions, through gestures and glances.

So, selecting for tameness, narrowly specified, brought in its wake tail wagging, floppy ears etc. The reasonable conclusion from this large scale change in traits is that they are causally linked. As the piece puts it (5):

What the Belayaev results suggest is that the manifold aspects of domestication might have a common cause in a gene or set of genes, which occur naturally in different species but tend to be selected out by adaptive and environmental pressures.

There is even a suggested mechanism: something called “neural crest cells.” But the details do not matter really. What matters is the reasoning: things that change together do so because of some common cause. In other words, common change suggests common cause. This is related to (but is not identical to) the discussion about Gs above. The above looks at whether G traits necessarily co-occur at any given time. The discussion here zeros in on whether when they change they change together. These are different diagnostics. I mention this, because the fact that the traits are not always found together does not imply that they are would not change together.

The linguistic application of this line of reasoning is found in Tony Kroch’s diachronic work. He argued that tracking the rates of change of various G properties is a good way of identifying parameters.[2] However, what I did not appreciate when I first read this is that the fact that features change together need not imply that they must always be found together. Here’s what I mean,

Think of dogs. Domestication brings with it floppy ears. So select for approachability and you move from feral foxes with pointy ears to domesticated foxes with floppy ears.  However, this does not mean that every domesticated dog will have floppy ears. No, this feature can be detached from the others (and breeders can do this while holding many other traits constant) even though without attempts to detach floppy ears the natural change will be to floppy ears. So we can select against a natural trait even if the underlying relationship is one that links them. As the quote above puts it: traits that occur naturally together can be adaptively selected out.

In the linguistic case, this suggests that even if a parameter links some properties together and so if one changes they all will, we need not find them together in any one G. What we find at any one time will be due to a confluence of causes, some of which might obscure otherwise extant causal dependencies.

So where does this leave us? Well, I mention all of this because though I still think that MP considerations argue against FL internal parameters, I don’t believe that the observation that Gs can treat these properties atomically is a dispositive argument against their being parametrically related. Changing together looks like a better indicator of parametric relatedness than living together.

Last point: common change implies common cause. But common cause need not rest on there being FL internal parameters. This is one way of causally linking seemingly disparate factors. It is not clear that it is the only or even the best way. What made Rizzi’s story so intriguing (at least for me) is that it tied together simple changes visible in main clauses with variation in (not PLD visible) embedded clause effects. So one could conclude from what is available in the PLD to what will be true of the LD in general.  These cases are where parameter thinking really pay off, and these still seem to be pretty thin on the ground, as we might expect if indeed FL has no internal parameters.

[1] There is another use of ‘parameter’ where the term is descriptive and connotes the obvious fact that Gs differ. Nobody could (nor does) object to parameters in this sense. The MP challenging one is the usage wherein FL prescribes a (usually finite) set of options that (usually, finitely) circumscribe the number of possible Gs. Examples include the pro-drop parameter, the V raising parameter, the head parameter.
[2] See his “Reflexes of grammar in patterns of language change.” You can get this from his website here. Here’s a nice short quote summing up the logic: “…since V to I raising in English is lost in all finite clauses with tensed main verbs and at the same rate, there must be a factor or factors which globally favor this loss” (32).

It's that time of year again

My daughter loved this time of year for its gift giving possibilities. Why choose Hanukkah over Xmas over Kwanza when you can celebrate all gift giving holidays. Ecumenism has its advantages, or so she would have had me believe (though not in these exact words). There is one other nice feature of this time of year: the opportunity to get together and celebrate and part of the festivities is often a skit. I recently got hold of a possible script for those who wish to cheer the season in with a distinctive GG accent. The dialogue is by John Collins (here) and after reading it, I cannot imagine a better way to ring in the seasonal joy. It hits all the high points and is even something that you can give (or better do with) friends and family that ask you to explain to them what you do. It is a tad rich on the conceptual underpinnings of the enterprise, but it provides a fine foundation for further talk about your latest paper that you can conduct over the dinner table. So, happy holidays and feel free to report how the performances went.

Sunday, December 11, 2016

Two more little provocative pieces

I ran across two more things of interest.

The first is this post on Gelman's blog that reviews a recent paper in PNAS suggesting that the standard stats used to interpret fMRI findings are very very unreliable ("the general message is clear: don't trust FMRI p-values"). Gelman provides what seems to me a reasonable set of comments on all of this, including another discussion of the perverse incentives favoring statistical abuse. However, there is another issue that gets shorter shrift. It appears that even seasoned practitioners have a very hard time applying the techniques correctly (unless we make the silly assumption that most everyone using FMRI over the last 30 years is a fraud). This suggests that we ought to be very skeptical about any stats based report about anything. What the recent replication problems indicate is that even the best labs have a weak grasp of their stats tools.

Coming from a field which is often lectured on the  primitive nature of its data collection techniques,
I admit to experiencing quite a bit of very pleasant schadenfreude reading that the biggest problem in science today seems to be coming from just the techniques that my own field of interest has done without.  IMO, linguistics has done very well despite eschewing statistical sophistication, or indeed statistical crudeness. Of course I know the response: the right use of these stats techniques is what linguistics needs. My reply: first show me that the techniques can be reliably applied correctly! Right now it seems that this is far from obvious.

Indeed, it suggests a counter: maybe the right position is not to to apply the hard to apply technique correctly but to figure out how to get results that don't rely on these techniques at all. Call this Rutherford's dictum: "If your experiment needs statistics, you ought to have done a better experiment." One of the happy facts about most of linguistics is that our experiments, informal as they are, are generally speaking so good as to not require stats to interpret the results. Lucky us!

The second post is an interview with Freeman Dyson. It is short and fun. He says threes things that I found provocative and I'd be interested to hear opinions on them.

The first is his observation that great teachers are ones that can "find the right problem for each student, just difficult enough but not too difficult." I think that this is indeed one important mark of a great graduate mentor, and it is not something that I myself have been very good at. It also focuses on something that we often tend to take for granted. The capacity to generate good solvable problems is as important, maybe more important, that being able to provide solutions to said problems. Getting the problem "right" is more than half the battle, IMO, but I suspect that we tend to identify and value those that do this less than we should.

Second, Dyson rails against the PhD as a useful academic hurdle. He never received one and considers himself lucky never to have been required to. He thinks it antiquated, too arduous, and too intellectually disruptive.

Up to a point I agree. Certainly the classical thesis which develops a single topic over 300 pages with extensive critical review of the literature is more aimed at fields where the book is the primary research vehicle. Many places have long since replaced the book with the "stapled dissertation" where several research papers on possibly diverse topics are a thesis. This does not mean that a long form single topic thesis is a bad idea, only that a paper-oriented dissertation is a legit option. What the long form provides that the stapled essays don't is an opportunity to take a broader view of the discipline in which one is becoming a professional. Once one is a professional then until one attains senior status, thinking big is often (always?) frowned upon. This might be the only chance many get to see forests and not just trees. That said, I'd be curious to know what my younger colleagues think. And what if anything could replace the PhD that would be fair and useful.

Last point Dyson raises is where originality comes from. His vote, ignorance.
First of all, it helps to be ignorant. The time when I did my best work was when I was most ignorant. Knowing too much is a great handicap.
One of the complaints that older people always have about their younger colleagues concerns how little they know. Don't they know that we've done this before? Don't they know about so and sos research? Don't they know anything about the field before [put in very recent date here]? At any rate, what Dyson notes is that knowing too much may well be a problem. In fact, growing knowledge, rather than loss of energy coming with age, maybe what slows down senior scholars.

Syntacticians have had an antidote for this until recently. Chomsky used to change the landscape every decade or so, unnerving past students and emboldening young'uns. When junior you loved this. If senior you grumped. If Dyson is right, what Chomsky did was a great service for the field for he made it possible to be legitimately ignorant: things have changed so being erudite was not that important. Dyson's view is that ignorance is not so much bliss as liberating, allowing one to think about issues in new ways. Is he right? I'm not sure, but then look how old I am.