It is hard to think of anyone who is in a better position to talk about bilingualism and aphasia (differential patterns of recovery and so forth) than Paradis. Since the 1970s, he has been a central figure in this area of research, and it is widely recognized that his contribution has been major. It is impossible to imagine any discussion of the topic that does not rely heavily on his work. Given this author's prominence in the field, second language (L2) researchers will find much to admire in this volume.

There is also much to agree with in this book. In particular, the cautions regarding the manner in which neuroimaging tools have been deployed to address questions of differential representation of two languages in the brain are timely and worthwhile. Apart from any other concerns, many of these studies, as Paradis reasonably points out, suffer from a lack of linguistic sophistication (unfortunately true of neuroimaging studies of language more generally).

Agreement might be more difficult to arrive at when it comes to the various proposals that Paradis lays out for an “integrated neurolinguistic perspective on bilingualism” (the importance of implicit vs. explicit memory, the relevance of motivation and affect, etc.; p. 187). These issues have been much discussed in the L2 literature, and researchers will no doubt have already formed quite clear views on whether, for example, Schumann and his amygdala are matters that could ever engage them. Rather than discuss these familiar issues, I will devote the remainder of this brief review to an issue that might be a little less familiar—namely, what is meant by neurolinguistics and why anyone should care about the enterprise, because it is here, in particular, that I would venture to dissent from the author.

To put it bluntly, what I miss in this volume's notion of neurolinguistic theory is anything theoretically linguistic. Linguistic, in this book, refers to anything but linguistic theory, which it shuns like the plague. It might also be noted that there is very little that is specifically neuro either. The role of the neuro appears to be restricted to the brute fact that language is processed in a brain as opposed to some other organ. Additionally, the term theory is used, it seems, to characterize the product of more or less any kind of thought, whereas some would prefer to reserve use of the term to refer to scientific theory.

So, what is the notion of neurolinguistic theory espoused by this volume? Paradis fosters the widely held idea that neurolinguistic theory is about various things: It is about verbal deficits due to brain lesions; it is about whether two languages have distinct neural representations; it is about language rehabilitation; and so on. The Linguistic Society of America's website description of neurolinguistics is entirely in the spirit of this book: “all of these questions and more are what neurolinguistics is about” (paragraph 3). Further, Paradis sees the compatibility of linguistic and neural theories as an early step that has paved the way for a neurolinguistic theory of bilingualism to be proposed in this volume (p. 1).

A rather different way of conceiving the neurolinguistic enterprise is that we have two bodies of knowledge—linguistic theory and brain theory—that we can only hope one day might be unified. At present, far from these theories being compatible, any possibility of unification seems utterly remote. So what can we do? The obvious thing we can do is to continue to develop linguistic theory and brain theory and hope that, as our understanding deepens, it will ultimately become possible to see how both theories might be mutually constrained. Another thing we can do is try to ask brains coherent questions about language, bearing in mind that the only coherent questions we can pose to a brain about language are those that find a place in linguistic theory. In this vein, we might ask a relatively simple question such as “Does the brain care about morphological roots in any way that we can measure?” The brain might respond in ways that seem uninterpretable, which is always a distinct possibility given the current levels of understanding. However, it might respond in a way that indicates that it does care about roots. In fact, it appears that a particular neuromagnetic component (the M350) might be an index of access to morphological roots. The component can be systematically moved earlier or later in time by varying relevant properties of words. The finding, although fascinating (to me, at least), is still largely mysterious, given that we lack a theory of brain that accounts for it.

Understanding is obviously very sparse, so it appears pointless to talk about theory at all in connection with neurolinguistics. Thus, far from being ready to formulate a neurolinguistic theory of bilingualism, we have barely the ghost of an idea of what a neurolinguistic theory of any aspect of one language would look like!

This volume can hardly be expected to endorse this view of neurolinguistics, in which linguistic theory is key, because the author is convinced that linguistic theory has achieved very little. Paradis alludes to “the repeated unsuccessful attempts of professional linguists over the past 40 years to characterize the simplest underlying syntactic algorithm” (p. 34). This is rather bad news because this book does not set the bar very high for what counts as knowledge, dismissing linguistic theory in favor of notions such as affect. Apparently, we know nothing about syntax, but we know plenty about human motivation. Worse still, linguists cannot agree with each other (p. 34), and the theory keeps changing (p. 36).

In response, it might be worth observing that linguistic theory had better keep changing or it is a dead theory—after all, it is the merest truism that all scientific theories are constantly changing. Similarly, there had better be disagreement; but the kind of disagreement that Paradis has in mind is rather different from normal scientific dispute. He sees the very existence of both generative and, say, stratificational linguists as a cause for throwing up one's arms in despair. First, I think it is fair to say that stratificational linguistics has very few adherents, but, independent of that, the issue at stake in any theory is insight. Does any given theory yield insight? Paradis' judgment is that linguistic theory has yielded zero insight, about which I have nothing to say.

However, whereas this volume cannot be expected, in light of the above, to consider the alternative view of neurolinguistics that I have sketched, adopting such a view helps to resolve some of the problems that this book highlights. Paradis claims that theoretical linguists prize elegance and economy above all (which, incidentally, is far from obvious) and argues that

Although reasonable, this is far from being an argument against linguistic theory in neurolinguistic inquiry; in fact, this is a recognition that there is a unification problem, which is what drives the alternative view of neurolinguistic inquiry. Similarly, when Paradis worries that “grammar rules are abstractions, not descriptions of actual cerebral computational procedures” (p. 34), it is useful to consider once again that the chasm that separates brain theory and linguistic theory is a problem of unifying these bodies of knowledge, not a reason for abandoning linguistic theory. Recognizing the true nature of the problem is a starting point, not the end of the line. For L2 researchers interested in examining this alternative view in more detail, let me recommend two articles that they might wish to read in conjunction with this book: Chomsky (1995) for discussion of the unification problem facing neurolinguistics and Phillips (2004) for some proposals regarding other challenges that neurolinguistic inquiry must meet.