This isn't a book by Noam Chomsky, it isn't really composed of interviews, and it contains no "science of language".

Yes, 44 per cent of it contains transcribed conversations between James McGilvray and Chomsky, but this isn't interviewing. Interviewers probe. McGilvray just gently nudges Chomsky to deliver mini-lectures. The preface characterises their chats as "like discussions between friends", but this strange mix of hopeful stimuli and rambling responses is like no discussion between friends I ever heard.

"Merge - the basic computational principle: how far down does it go?" asks McGilvray.

Chomsky responds: "Whatever the lexical atoms are, they have to be put together, and the easiest way for them to be put together is for some process to just form the object that consists of them. That's Merge. If you need more than that, then ok, there's more - and anything more will be specific to language."

"So in principle," says McGilvray, "von Humboldt might have been right, that the lexicon is not this - I think his term was 'completed, inert mass'..."

Chomsky breaks in: "...but something created..." (the ellipsis dots are McGilvray's).

McGilvray accepts the prompt: "...something created and put together. But if it's put together, is it put together on an occasion, or is there some sort of storage involved?"

"It's got to be storage. We can make up new words, but it's peripheral to the language." (Here McGilvray amends Chomsky's "language" to "language [system's core computational operations]".)

It continues thus, jargon jostling with loose conjecture and dogmatic assertions. Chomsky avers that words never refer to anything in the world; that "the entire discussion of the last century or so" about relations between physics and chemistry "was crazy"; that Darwin was wrong and evolution by natural selection (like Skinnerian behaviourism) cannot work; that there was no "serious research" on morality before 2000; that the practice of debating "is a tribute to human irrationality"; etc.

Chomsky's musings are often familiar from other recent collections of transcribed dicta, e.g. in The Architecture of Language (2000) or Of Minds and Language (2009). For example, he claims that children have an innate grasp of the psychic continuity of persons, and his basis for the claim is that his grandchildren enjoy a story in which a baby donkey gets turned into a rock. It is surprising to see a point this feeble published even once, but Chomsky has now put it into print at least three times.

There is heavy internal repetition, too. Chomsky repeats thrice over that a conjectured mental operation called "Merge" popped into human brains 50,000 years ago via a "genetic modification" that "happened in a single person" and "rewired the brain slightly".

"Merge" is a posited binary operation that (as Chomsky puts it) "simply says, take two things, and construct a thing that is the set of the two things".

Instead of asking why we needed a brain mutation for something as elementary as the notion that two things can be put together to make a set of two things, McGilvray invites Chomsky to explain how "Merge" brought humanity the gift of arithmetic.

The attempted exposition is a train wreck. Chomsky confuses the empty set with zero, binary operations with unary ones, functions with the sets on which they are defined, the natural numbers with their set-theoretic construction, and both with the theory of arithmetic. McGilvray drinks it all in - and appends a commentary note that unfortunately elaborates the second of Paul Benacerraf's two celebrated non-equivalent set-theoretic reconstructions of the natural numbers, when Chomsky was struggling to outline the first. It is embarrassing - like overhearing a conversation between two undergraduates about a mathematics lecture that neither has understood.

Following the 141 pages of transcribed chunks of conversation are some lengthy appendices and commentary notes, mostly just pedestrian restatements of Chomsky's increasingly eccentric linguistic doctrines, and together with the glossary, bibliography and index making up 56 per cent of the whole book.

At least half a dozen "interview" volumes of Chomsky's unrehearsed musings have been published since Mitsou Ronat created the genre in 1977. This one is McGilvray's fourth book-length homage to Chomsky by my count. He is entitled to his view that anything Chomsky can be induced to say should be typed up and distributed. But why are university presses publishing stuff like this, devoid of carefully framed ideas, results or scientific data about language?

Presumably the guaranteed sales from having Chomsky's name on the cover are too tempting to resist. Buyers should beware.