In response to LINGUIST List Reviews issue: 
http://linguistlist.org/issues/18/18-432.html#1 
 
Like booing and jeering at sports events, negative reviews are part of the 
culture of the humanities and social and behavioral sciences. A standard 
technique is to describe a book the reviewer would like to have read. 
 
Michael Arbib has written extensively on mathematics, models of the brain 
and computational science but his website and publications indicate no 
previous interest in language variation, acquisition or change. Not 
surprisingly, he wanted a textbook on historical linguistics (actually, a 
construction-based approach), providing a comparison of alternative 
theories and an account of how work on historical phonology might develop. 
 
Now there is a textbook on diachronic syntax (Roberts 2007). This will 
provide part of what Arbib wants but not everything – it, too, fails to 
adopt a construction-based approach and also ‘is silent on how to move 
forward the study of historical phonology.’ 
 
My goal was not to write a textbook or a monograph but a book intended for 
people in other disciplines about how new languages emerge, motivated in 
part by a belief that linguistics allows a more sophisticated treatment of 
history and change than has been obtained in biological or political 
history. The book makes much of the distinction between “external 
language” (language as it exists in the world) and “internal language” 
(language as represented in an individual’s brain). By examining the 
interplay between the two, in ways that differ from my earlier work, I 
showed how children are “cue-based” learners, who scan their linguistic 
environment for specified structures, making sense of the world outside in 
order to build their internal language. In my view, the cue-based approach 
to acquisition is a significant variant of other parametric approaches, 
which solves problems in those approaches. There were new ideas about the 
EXPRESSION of cues and I explored how new systems arise, how they are 
acquired by children, and how adults and children play different and 
complementary roles in language change. 
 
One is generally advised not to reply to reviews. Here I merely state 
briefly the intent of the book, as stated in the publisher’s blurb and in 
the first few paragraphs of the preface, because nobody reading Arbib could 
have any idea what the book is about. He did not understand the most 
central notions. 
 
He writes that children construct an I-language that approximates the 
ambient E-language, but that is inconceivable: E-language is a different 
kind of thing from I-languages. For example, I-languages have structures 
but E-language is a collection of utterances. 
 
Poverty-of-stimulus arguments are central in my work and he complains that 
I do not respond to the criticisms of Pullum & Scholz (2002), not 
remembering that Pullum & Scholz explicitly exclude discussion of the kind 
of arguments that I have been concerned with, which they characterize 
accurately as ‘not so much stimulus poverty as stimulus absence’ (pp14-16). 
 
He says that ‘no theory is offered of how the child activates “cues” from 
the observed E-language,’ ignoring discussion of the expression of cues. 
He may not like that theory but a theory is discussed. 
 
He writes: ‘His method is to simply observe that a change occurs in the 
texts from date x to date y and then state without evidence that change in 
children’s I-languages must have been the driving factor … And that’s the 
method – gather data showing historical change, then argue that I-languages 
might change as a result, and then assert without discussion that the 
change in I-languages explains the E-language change.’ 
 
This is so topsy turvy that it’s hard to know where to begin. Certain 
historical changes cluster and can plausibly be shown to reflect a single 
change at the level of I-languages. The clustering of phenomena changing 
at the same time is the evidence for the singularity of the change in 
I-languages. So modal verbs in English came to be categorized as 
Inflectional elements in Early Modern English; several phenomena changed, 
which can be construed as a function of that single change in I-languages. 
 Thomas More was the last known speaker with the old system and all the 
relevant phenomena occur in his extensive writings. Others had the new 
system before More’s time. In general, speakers either had the old system 
or the new system or, for a transitional period, both systems, but the 
phenomena cluster systematically and not randomly. Given such an analysis 
of I-language change, one can look for prior changes, changes in adult 
usage, which changed E-language in such a way that the new system came to 
be triggered, thereby EXPLAINING the change in I-languages. Hence the 
interplay between adult changes and changes in acquisition by young 
children, and the complementarity of adult and child changes. There was no 
attempt to ‘privilege the language learning of infants over the effects of 
adult innovation’ and I do not ‘insist without question that children’s 
formation of new I-languages is the key to how languages change.’ The two 
kinds of change, change in E-language and I-languages respectively, work 
off each other – both are essential and there could be no change in 
I-languages without prior change in E-language. 
 
There is much to say about all of this, much that has been written in the 
technical literature. However, I regret that Arbib was not able to find 
the book he was looking for and yet more that I was not clear enough for 
him to understand the central notions of the book I wrote. 
 
REFERENCES 
Pullum, G. K. & B. C. Scholz 2002 Empirical assessment of stimulus poverty 
arguments. The Linguistic Review 19:9-50. 
Roberts, I. G. 2007 Diachronic syntax. Oxford University Press.