Book of a Lifetime: The Anathemata, byDavid Jones

I first read this extraordinary, book-length poem while conducting a traffic census around Newbury in 1980 (it turned out to be the first step towards the infamous by-pass). The odd car or lorry became an annoying interruption: I was gripped. This is strange, as the poem is mostly, at first glance, incomprehensible. It was described by its author, rather mischievously, as a free-association record of what might pop into his mind during mass, sparked by the words of the liturgy. It is, in fact, a kind of spiritual history of the West.

For this solitary artist-poet, deeply damaged by the First World War, language was an ancient site full of "deposits". Thus the title itself means "devoted things", but holds its opposite – "anathema", or hated things – within it.

When a poet handles language, he or she is always touching the past, if only etymologically. When the poet is David Jones, for whom the past was perpetually present through Christ's sacrifice, then the result is a species of time travel. In fact, I look upon The Anathemata, first published in 1952, as a life-changing spell (and I am not Catholic). Sounding the deeps of Iron Age Cornwall, Tudor London, Penda's Mercia or the Welsh "Otherworld", the words work profound seams in the brain. Sweeping up cockney, Greek, Latin, Welsh, fragments of song and prayer or shipwright terminology, the lines are harnessed out of chaos by Jones's visionary narrative, as directed as the liturgy itself.

If this sounds over-intellectual, it is quite the opposite: The Anathemata is a passionate poem, deeply spiritual and sensuously material, a weird mingling of paganism and Catholicism, sea voyage and landfall. For Jones, modern industrialised society had lost the sense of the sacred, and it was through the materia poetica that it might be rediscovered: an answer to our longings. And he insists in his Preface that there must be "no 'mugging-up', no 'ought to know' or 'try to feel'". Thus the work is uncompromisingly itself – even dottily so – with its lower layer of footnotes, its passages in square brackets, its Shakespearean neologisms and yokings ("un-apsed", "god-stones").

As the primary focus of the poem is Britain, the sea washes around and through it in a ceaseless surge; Jones is as good as Melville in Moby-Dick at evoking water, even when it is locked in ancient glaciation or seething off a medieval boat: "Now north by east/over the nine white grinders/riding the daughters of the quern of islands/kouroi from over yr eigion [the deep]." He even makes "the barrier-making flood-gravels/the drumlined clays and the till-drift" feel sacred, likening glacial action to the breaking of the host in one of his myriad footnotes – whose plain English comes to feel almost strange, in the end.

Adam Thorpe's new novel is 'The Standing Pool' (Cape)