After Nature by WG Sebald, Trans. Michael Hamburger

After Nature, WG Sebald's first literary work, came out in German in 1988. Then it had a subtitle "Ein Elementargedicht" (meaning elementary or elemental poem, or poem about the elements) – which needed elucidation and, perhaps for that reason, has been omitted in this English publication.

Is After Nature a poem? Is it even a prose poem? Its sentences are set out as verse: short lines, unrhymed, in no metre, of very irregular, mostly undistinguished rhythm, the line-breaks rarely serving any poetic purpose. What the lines do, in German and in Michael Hamburger's characteristically close translation, is emphasise the peculiar articulations of a highly mannered prose. Having done it this way once, Sebald thereafter set out his unconventional prose conventionally.

The book consists of three densely composed biographies: of the 16th-century painter Matthias Grünewald, the 18th-century botanist Georg Wilhelm Steller, and the author himself. The whole work is "elementary" in that it makes a beginning on themes and matter that would obsess Sebald for the rest of his writing life; and does so through techniques of association, juxtaposition and montage that became his hallmark. In all three life histories, the elements – forces and phenomena of the natural world – are very powerfully present. Steller accompanies Vitus Bering on the unhappy Alaska expedition in 1741, and watches captain and crew sicken and rot in wind and weather. Grünewald paints his disgusting crucifixions in revulsion at the physical world and at man's plague-ridden, war-torn, sin-sickened existence in it.

Then Sebald himself: born in southern Germany in 1944 and dying far too soon under the vast and somehow annihilating skies of East Anglia. Lines addressed to his daughter in this final history have a poignancy unforeseeable when he wrote them and even when, only last year, he approved Hamburger's translation. Yet their pathos is very much in keeping with the melancholy spirit of the whole. The author's own death (last December) finishes the book posthumously, in an aptly cruel way.

For the premise is our helplessness in a world we never made; a world that is one vast pullulating organism, going its own way according to its own laws and absolutely not there for our comfort. Nature, says Sebald's Grünewald, is "a senseless botcher"; life on earth "an evil state of erosion/ and desolation". Small wonder that he wants redemption "from life itself". In the second fictional biography, Steller hears this verdict from the Orthodox primate: "All things, my son, transmute/ into old age, life diminishes,/ everything declines,/ the proliferation/ of kinds is a mere/ illusion, and no one/ knows to what end".

In that natural and philosophical context, man's own atrocities – a massacre of peasants at the Battle of Frankenhausen, pogroms in Frankfurt in 1240 and 1349 – are incidental worsenings of an unbearable situation. Later, Sebald will bring such things centre-stage. This work is elementary in that he here sets out the primal circumstances in which we act.

Later, surveying our actions in more detail, he became, like so many writers born in the atrocious 20th century, "a hieratic witness to evil". That is martyrdom, and there may be heroism in it too. Art often partakes of both. Grünewald, as depicted here, though Sebald calls him a witness, testifies chiefly to his own fear and loathing. Sebald says that he "rendered the scream, the wailing, the gurgling/ and the shrieking of a pathological spectacle/ to which he and his art, as he must have known,/ themselves belong".

Is that heroic? I suspect Sebald of thinking so. Steller is a more sympathetic candidate for absurd heroic status, determinedly collecting, naming and classifying botanical specimens in conditions inimical to the human being's bare survival. And Sebald's own writing, somewhat more on the side of humanity than Grünewald's painting, is certainly – in its contrivance, intricacy, learning, intelligence and connectedness – a sign and an admonition for our times.

David Constantine's latest volume of poems, 'Something for the Ghosts', is published by Bloodaxe