Bickerton (2000), reviewing my book The Origins of Complex Language (1999), accuses me of failing to explain certain aspects of language, especially recursion, and of offering explanations for other aspects of language that really do not need any explanation, notably the syntactic distinction between sentences and noun phrases. I argue that these criticisms are misplaced. They reflect partly a misunderstanding of the logic of my argument and partly a confusion between semantics and syntax.
(a) I omit to explain certain aspects of language that are central characteristics of it today.
(b) I take an idiosyncratic approach to the continuist- discontinuist issue.
(c) Some of the aspects of language that I try to explain are not really problematic at all.
(d) The structural resemblance between syllables and sentences that I seek to exploit is illusory.
I will deal with the four kinds of criticism in turn, arguing that nearly all of them miss their mark.
2. Bickerton points out correctly that I have almost nothing to say about what he calls "perhaps the most basic property of syntax", namely recursion. (It is no surprise, then, that I have nothing to say about properties of syntax that are solely or mainly instantiated in recursive structures, such as control, binding, and empty categories.) This would be a valid criticism if either (a) recursion were a property of syntax that I set out to explain, or (b) recursion were fundamental to an explanation for any property of syntax. But (a) is not the case, as Bickerton acknowledges. As for (b), I take pains, in chapter 2 especially, to show that there are imaginable alternatives to actual syntax that display recursion, yet differ fundamentally from actual syntax, notably in lacking any counterpart to the familiar distinction between 'sentence' and 'noun phrase'. Therefore, the fact that actual syntax displays recursion cannot explain why it differs from these imaginable alternatives.
3. My failure to explain recursion is no more 'Micawberish' than Bickerton's failure, in his own works on language evolution, to explain why seemingly arbitrary inflection classes ('declensions' and 'conjugations') are such a robust characteristic of many languages. In fact, precisely because inflection class systems are so seemingly useless from the point of view of the contemporary functions of language, they stand a good chance of being what Dennett (1995) calls a 'QWERTY phenomenon', and thus more revealing of linguistic prehistory than a characteristic such as recursion whose current usefulness is so evident.
4. Now to (dis)continuism. Are the words of spoken language descended from the vocalizations that were being produced during the time when the lowering of the larynx was rendering them progressively more human-like, with formant patterns to distinguish vowels and with successive widenings and narrowings of the vocal tract to yield syllables? I consciously use the word 'vocalization' here, rather than either 'call' or 'word', because each of these latter carries a freight of assumptions: animal 'calls' are generally said to be instinctive, context-bound and limbically controlled, while human 'words' are learned, susceptible of displacement, and cortically controlled. For Bickerton, however, these vocalizations must be either 'calls' or 'words' , with the respective characteristics just described; and neither choice is satisfactory (he claims). If they are words, then the origins of language are "push[ed] ... back into the mists of time, leaving them totally mysterious". If they are calls, then the constellation of characteristics just described precludes their development into the words of language (supposedly).
5. There are two issues here. The first is whether the difference between words and calls is and always has been clearcut. By no means all anthropologists and neuroscientists agree with Bickerton on this (see e.g. Steklis 1988; Deacon 1997, chapter 8). But, even supposing that Bickerton is right, his own approach renders the evolution of 'words' no less mysterious than mine does. According to him, the use of words involves a 'secondary representational system' in the brain, distinct from the 'primary representational system' in terms of which all animals' experience is organized. But he describes only two secondary representational systems, both of them strongly linked to some form of language: one associated with modern human language and one associated with 'protolanguage', that is, the sort of syntactically impoverished language evidenced in early childhood, in some pidgins, and (Bickerton suggests) in the linguistic behavior of 'Homo erectus'. Thus, linking the origin of words to secondary representational systems involves a strong element of circularity, and scarcely resolves any mystery. To complicate matters further, Bickerton is happy to agree that some contemporary nonhuman animals can achieve at least some proficiency in protolanguage, notably apes trained in the use of sign language or lexigrams. To that extent, therefore, even a chimpanzee can use 'words'; so it seems arbitrary for Bickerton to deny 'word' status to the vocalizations I described in the previous paragraph.
6. As a further supposed obstacle to my scenario, Bickerton mentions predication. If the vocalizations described in paragraph 4 above are really words, they ought to be combinable so as to yield subject- predicate structures such as 'Dogs bark' or 'John left'. It is unnecessary to appeal to syllable structure as the exaptive source for this sort of basic sentence structure, Bickerton thinks, because "why would you have to wait for the larynx to drop in order to concatenate things like that?" But Bickerton here neglects the obvious counter-question: If this sort of concatenation is so straightforward, why are humans the only species to achieve it? Bickerton may answer: 'Because only words can be concatenated, not calls, and only humans use words'. But that is merely to push the question one stage further back, so that it becomes: Why do only humans use words? And, as we have seen, Bickerton's invocation of 'secondary representational systems' to answer that question is less than satisfactory.
7. Predication brings us to the third category of complaint. Predicates are typically verbal while arguments are typically nominal, and the combination of a predicate (e.g. 'captured') with the appropriate number of arguments (e.g. 'the Goths' and 'Rome' ) yields a sentence ('The Goths captured Rome'); so, if predication is straightforward, the distinction between sentences and noun phrases (NPs) must be straightforward too, and my syllable-derived scenario to explain it is superfluous, Bickerton argues. As he puts it: "Surely there are enough problems in language evolution without inventing new ones." But here Bickerton makes the fundamental mistake of confusing a semantic representation with its syntactic expression. A semantic predicate-argument structure involving Rome, the Goths and capturing can indeed be expressed syntactically by means of a sentence containing a verb, but it can also be expressed by means of a NP containing no verb ('the capture of Rome by the Goths'). Moreover, one can envisage kinds of language in which its expression is neither sentential nor nominal, simply because in these languages no syntactic contrast between sentences and NPs exists. One may be tempted to think that such languages would be somehow deficient because the sentence/NP distinction is motivated by a distinction between 'asserting' and merely 'referring' , or suchlike -- but that is a mistake, because (as I argue in chapters 2 and 3) the distinction between assertion and reference turns out, when examined, to have no basis independent of the syntactic distinction between declarative sentences and NPs. That is an important aspect of my argument that Bickerton ignores entirely. To compare language-as-it-is with language-as-it-might-have-been is not to invent unnecessary new problems, as he seems to think; rather, it is the only way to gain insight into what needs to be explained, given that there are no intelligent non-language-users (Martians, say) who might point this out to us with the benefit of an outsider's perspective.
8. Bickerton's other complaints in the third category rely on two fallacies: firstly that, in evolution, necessity is the mother of invention, and secondly that invention is the child of necessity. (If the first were true, humans would have developed the ability to fly and to live on grass, since these capacities would have been so obviously advantageous to our savannah-dwelling ancestors competing for survival with large carnivores. If the second were true, there would be some advantage in having blood that is red rather than, say, green in color.) When Bickerton argues that without duality of patterning "you could never get enough words to represent everything in the primary representational system", he commits the first fallacy, because he neglects the possibility that words, like wings, might have remained entirely outside our evolutionary reach. When he argues that human language vocabularies are large because 'a secondary [representational] system, such as language, cannot be stopped from representing everything that is in the primary system' , he commits the second fallacy, because he neglects the possibility that a large vocabulary may be byproduct of some other adaptive characteristic, just as the color of blood is a byproduct of its composition. So these are genuine problems, not spurious ones, whether or not my solutions to them are convincing.
9. Bickerton's fourth kind of complaint involves the alleged similarity between syllable structure and basic sentence structure. This similarity is illusory, he says. If so, I am not the only linguist to have succumbed to the illusion. However, there is a genuine issue underlying Bickerton's complaint. If, as I admit, the fit between syllable structure and contemporary sentence structure is far from exact, how is one to determine the closeness of fit that is necessary to render my hypothesis about the origin of syntax plausible? Am I not bound to skew the determination so as to ensure a favorable outcome? That is certainly a risk when one is dealing, as here, with an area of inquiry where exactly what needs to be explained is as much at issue as the explanations offered. But I have tried to minimize the risk by showing how easy it is to envisage alternatives to syntax-as-it-is that would be much less easily explainable in terms of syllable structure. For Bickerton's complaint here to succeed, he must show not merely that actual sentences are not much like syllables, but also that actual sentences are no more like syllables than are hypothetical sentences framed according to those alternative syntactic groundrules. If I am wrong, this should be a relatively easy task. Unfortunately, Bickerton has not attempted it.
10. Finally, Bickerton complains that 'an analogy is not an explanation'. He thinks that it is incumbent on me to show how a neural organization for motor articulatory processes could become involved in the sequencing of lexical items. Not being a neurophysiologist, I cannot do that. However, the neurophysiologist William Calvin has invoked just such a functional innovation as part of his own theory of how syntax arose (Calvin 1993), so I am confident that the innovation that I propose is neurologically plausible. Moreover, in a book of which Bickerton is the co-author (Calvin and Bickerton 2000), Calvin still maintains the view that a 'structured utterance planner' could have evolved out of a 'ballistic movement planner'. This makes Bickerton's complaint all the more strange. I differ from Calvin only in that the movements in question are specifically those of the vocal apparatus, I suggest.
11. To have the benefit of criticism from so distinguished a language evolution pioneer as Bickerton is a privilege for any researcher in this field. For me it is reassuring to find that his criticisms can be so easily answered.
Bickerton, D. (1990) Language and species. Chicago: University of Chicago Press.
Bickerton, D. (1995) Language and human behavior. Seattle: University of Washington Press.
Bickerton, D. (2000) Calls aren't words, syllables aren't syntax. PSYCOLOQUY 11(114), ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/2000.volume.11/ http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?11.114
Calvin, William H. (1993) The unitary hypothesis: a common neural circuitry for novel manipulations, language, plan-ahead, and throwing? In: Tools, language and cognition in human evolution, ed. by Kathleen R. Gibson and Tim Ingold, 230-50. Cambridge: Cambridge University Press.
William H. and Bickerton, Derek (2000) Lingua ex machina: reconciling Darwin and Chomsky with the human brain. Cambridge, MA: MIT Press.
Carstairs-McCarthy, A. (1999) The origins of complex language: an inquiry into the evolutionary beginnings of sentences, syllables and truth. Oxford: Oxford University Press.
Carstairs-McCarthy (2000) The origins of complex language. PSYCOLOQUY 11(082), ftp://ftp.princeton.edu/pub/harnad/Psycoloquy/2000.volume.11/ http://www.cogsci.soton.ac.uk/cgi/psyc/newpsy?11.082
Deacon, T. (1997) The symbolic species: the co-evolution of language and the human brain. New York: Norton.
Dennett, Daniel (1995) Darwin's dangerous idea. New York: Simon & Schuster.
Steklis, Horst D. (1988) Primate communication, comparative neurology, and the origin of language reexamined. In: The genesis of language: a different judgement of evidence, ed. by Marge E. Landsberg, 37-63. Berlin: Mouton de Gruyter.