Friday, October 26, 2012

The Rationalism of Generative Grammar

 The theory of mind that Generative Grammar endorses is evidently rationalist. An earlier post gestured (don’t you love that word!) to these philosophical roots. Interestingly (though not surprisingly), the scientific metaphysics is as well. Here’s what I mean.

I was recently reading a fascinating book by Nancy Cartwright -The Dappled World- (highly recommended for philo of science aficionados) in which she contrasts the role of powers/natures/capacities versus regularities in scientific theory.  The classical empiricist/Humean tradition rejected the former as occult residues of an earlier search for Aristotelian essences and insisted on founding all scientific knowledge on “the kinds of qualities that appear to us in experience (79)” (recall the dictum: nothing in the intellect that is not first in the senses!). Modern empiricists/Humeans endorse this antipathy to “powers” by treating the laws of nature as summaries of “what things do (82).” Cartwright contrasts this with the view that laws are about powers/natures/capacities, which is not about what things do but “what it is in their nature to do (82).” Here’s a quote that provides a good feel for what she has in mind:

What we have done in modern science, as I see it, is to break the connection between what the explanatory nature is- what it is in and of itself- and what it does. An atom in an excited state, when agitated, emits photons and produces light. It is, I say, in the nature of an excited atom to produce light. Here the explanatory feature –an atom’s being in an excited state- is a structural feature of the atom…For modern science what something really is -how it is defined and identified- and what it is in its nature to do are separate things.

In short, there is an important metaphysical distinction that divides Empiricists and Rationalists. For the former the laws of nature are in effect summaries (perhaps statistical) of “actually exhibited behaviors”, for the latter they describe abstract “configurations of properties” or “structures.” These latter underlie, but are distinct from, behavior (“what appears on the surface”), these being “the result of the complex interaction of natures (81).”

Cartwright notes the close connection between the Rationalist conception of powers/natures/capacities and the analytic method of inquiry characteristic of the physical sciences, often called “Galilean idealization.” She also provides several interesting reasons for insisting on the distinction between what something is versus what it does. Here are two.

First, given that visible behavior is an interaction effect of complex natures it is often impossible to actually see the contribution of the power one is interested in, even in the very contrived circumstances of controlled experiments. She illustrates this using Coulomb’s law and the interfering effects of gravity. As she points out:

Coulomb’s law tells not what force charged particles experience but rather what it is in their nature, qua charged, to experience…What particles that are both massive and charged actually experience will depend on what tendency they have qua charged and what qua massive (82).

Thus, actual measurable forces are the result of the interaction of several powers and it takes great deal of idealization, experimentation, calculation and inference to (a) simply isolate the effects of just one and segregate it from everything else, viz. to find out how two charged bodies “ ‘would interact if their masses were zero.’ ”[1]  And (b) to use the results from (a) to find out what the actual powers involved are:

The ultimate aim is to find out how the charged bodies interact not when their masses are zero, nor under any other specific set of circumstances, but how they interact qua charged. 

Second, contrary to the accepted wisdom more often than not in the real world the same cause is not followed by the same effect.  In fact, generating stable relations between cause and effect requires very careful contrivance in manufactured artificial experimental settings.  Cartwright refers to these as nomological engines; set-ups that allow for invariant regular connections between what powers/natures/capacities can do and what they actually do. Except in such settings the Humean dictum that effects regularly follow causes is hardly apparent.

Outside the supervision of a laboratory or the closed casement of a factory-made module, what happens in one instance is rarely a guide to what will happen in others.  Situations that lend themselves to generalizations are special…(86).
Now, the punch line: Cartwright’s discussion should sound familiar to generative ears. Chomsky’s important distinction between competence and performance is a rationalist one.  UG is a theory of human linguistic powers/natures/capacities, not a theory of linguistic behavior.  UG is not a summary of behavioral regularities. Indeed, linguistic behavior is a very complex interaction effect with competence being one of many (very poorly understood) factors behind it. The distinction between what a speaker knows (competence) and what a speaker puts this knowledge to use (performance) echoes Cartwright’s rationalist themes. Similarly, the rejection of the idea that linguistic competence is just (a possibly fancy statistical) summary of behavior should be recognized as the linguistic version of the general Rationalist endorsement of the distinction between powers/natures/capacities and their behavioral/phenomenal effects. Lastly, the Rationalist conception buttresses a reasonable skepticism against a currently common (and sadly fashionable) view that language acquisition is largely a statistical exercise where minds track environmental regularities, a view more congenial with the empiricist conception that identifies what something is with what it does. This cannot be true: for there are precious few such regularities in the wild and what there is won't (in fact cannot) alone reveal the powers, capacities and natures of the underlying object of linguistic interest, i.e. the fine structure of UG.

[1] Cartwright observes that though doing (1) is difficult it is “just a stage; in itself this information is uninteresting.” (83-4), a point not unlike that made in a previous post.


  1. In this blog you venture into philosophy of science and reveal very limited understanding of what you call the “Humean dictum”. I was unaware that outside of philosophy classrooms anyone would propose, “that effects regularly follow causes is hardly apparent”? You seem to think that Nancy Cartwright has not merely claimed but proven this and cite her:

    Outside the supervision of a laboratory or the closed casement of a factory-made module, what happens in one instance is rarely a guide to what will happen in others. Situations that lend themselves to generalizations are special…(86).

    Some may doubt Cartwright has the god-like authority you attribute to her. So, may I suggest a simple thought experiment to cure you from Pyrrhonian skepticism? Picture yourself at the top floor of a 30-story building. Open the window and jump out. Surely, from the fact that in the past people who did similar things fell to the ground, we should not jump (pun intended) to the conclusion that this effect would occur now. In fact we have no idea what might happen: “what happens in one instance is rarely a guide what will happen in others”. You might rise to the heavens or float unsuspended in mid-air or grow wings and fly away.

    Should you actually hesitate: congratulations – you recognize the silliness of taking Cartwright’s quote out of context and applying it to entirely unrelated areas of discourse, such as generative grammar. But in case you truly believe what you wrote, and are tempted to do the experiment outside your armchair, I beg you: PLEASE don’t! In the ‘real world’ such silliness can have deadly consequences.

    Now, if you have legitimate complaints about proponents of a "view that language acquisition is largely a statistical exercise where minds track environmental regularities" please cite the actual work and then demonstrate [i] where is went wrong and [ii] how minimalism can better account for the phenomena, especially how minimalism links language acquisition to biology.

  2. Yup, I think that Cartwright has made her case. Indeed that's why I cited her so that others could follow up on her points.

    Fear not, I won't jump. However, as you no count know, the grain of the generalization will matter. Drop a ball out a window and it will fall but will depend a lot on what it's made of. Ping pong balls don't fall nearly as hard as lead one's do (unless of course you drop them in a vacuum). Similarly, dropping an eagle will often crate no thud at all. My point, and Cartwright's is that the generalizations that lend themselves to generalizations of scientific interest are manufactured. They are the products of very artificial circumstances. This is Cartwright's point and I think that she is dead right. I could cite my favorite historians and philosophers of science and you can no doubt cite yours. But rather than do that i thought I would do something else: make clear the rationalist metaphysics that generative linguistics of the kind I value presupposes and show how it relates to scientific inquiry in other (more successful) scientific domains. That's enough for me. I doubt that these are matters over which persuasion is possible. Some people think that the world has a structure and the structure it has determines what happens. Some people think that things just happen: it's just one damn thing after another. I like the first view and want to show that it is neither idiosyncratic to linguistics nor that it is nutty. If you like the second one, there is really nothing I can say to dissuade you. It just strikes me as so boorrring! But there's no accounting for taste (though there is every reason to argue about it).

  3. So you disagree with Chomsky then who wrote [about externalization]: "I think there’s every option open from a perfect solution to a minimax problem to a worst possible solution, which is one damn thing after another. Anywhere in there could be some kind of answer to this question." [2009, p. 386] - you do not think every option is open because "the world has a structure and the structure it has determines what happens". It may come as a surprise but I agree and think Chomsky is wrong to claim that 'there is every option open'.

  4. I believe that he thinks that a priori any of these answers is possible even fixing what he believes holds for UG. That is different from whether the system allows every possible solution to the mapping. You need to be careful to distinguish when Chomsky is discussing the state of our knowledge and when he is discussing research directions. This is not that tough to do when you know something about the field. It is far more challenging if you don't.