The Incas built well. Though they never invented the wheel, they contrived to haul huge blocks of stone, often weighing 20 tons or more, to the mountain peaks they favored for their citadels. The slabs are so perfectly cut and positioned that not even a thin sheet of paper can be slid between them. The conquistadors added their own masonry to these ancient structures. Their work is slipshod by comparison. During an earthquake in Cuzco, Peru, the stone walls of the conquerors tottered and collapsed. The underlying Incan masonry stood fast. Andean stone, it would seem, possesses a justice all its own.

Stones are strewn through the work of Peru’s greatest modern poet. In “The Black Heralds,” his first collection, César Vallejo celebrated their inconspicuous strength:

Stones do not offend; they covet nothing. They solely ask love of everybody, and they ask love of even Nothingness.

Vallejo’s most famous poem is entitled “Black Stone on a White Stone.” When he wrote it, toward the end of his short life, he felt he had himself become something of a stone, a stray thing to be idly kicked aside. The poem begins:

I will die in Paris in a downpour, a day which I can already remember. I will die in Paris — and I don’t budge — maybe a Thursday, like today, in autumn.

In fact, Vallejo did die in Paris, on April 15, 1938. The day, appropriately for this poet of human suffering, was Good Friday. By then, having become a stone, a human stone, he could see his own life from a timeless vantage point — he could “remember” a day which had not yet dawned, the day when he would die.

Vallejo did to the Spanish language what earthquakes did to Spanish masonry. He sent it flying, exploding verbs, twisting nouns, subverting New World Castilian with slang, neologisms, and fragments of Quechua, the indigenous language of the northern Andean region, where he was born March 16, 1892. His poems pulverized Spanish, then reassembled it, often in fantastic ways. How can such a poet, who baffles Spanish readers as much as he electrifies them, be translated into English?

The answer seems to be, only by the work of a lifetime. Clayton Eshleman has now accomplished this feat in “César Vallejo: The Complete Poetry” (University of California Press, 730 pages, $49.95). Mr. Eshleman has been wrestling with Vallejo’s impossible poetry for nearly 50 years. (I still recall the impact of his early version of Vallejo’s “Human Poems,” published by Grove in 1968.) The present volume offers Vallejo’s four books in definitive versions, most of which have been revised, corrected, and polished dozens of times over the decades. It contains as well a foreword by Mario Vargas Llosa, an illuminating introduction by Efraín Kristal, a detailed chronology by Stephen M. Hart — the latter are both leading Vallejo scholars — notes, a bibliography, and a moving “Translation Memoir” by Mr. Eshleman.

Mr. Eshleman remarks of Vallejo that “the man I was struggling with did not want his words changed from one language to another.” His translations thus represent struggles with a stubborn ghost, and are all the better for it. When Vallejo invents the untranslatable verb “to autumn” (“otoñar”) in the line “and the cattle-bells autumn with shadow,” Mr. Eshleman recasts it as “the cattle-bells are autumncast with shadow,” a lovely solution. But his true ingenuity shows in his handling of Vallejo’s notorious “experimental” verse.

“Trilce,” the collection which appeared in 1922, teems with made-up words, nonsense, deliberate gibberish, stammers, and exclamations. Early readers denounced it as “incomprehensible,” but it seems less so nowadays. Lines such as “I sdrive to dddeflect at a blow the blow” or nonce-words like “transasfixiate” or “constringe” may seem self-indulgent, like much of the late poetry of Paul Celan (with whom Vallejo is often compared). And yet, “Trilce” (the name denotes “an ineffable location in the mind”) not only freed Spanish poetry from its petrified constraints, it freed Vallejo too.

“The Black Heralds,” begins with the line, “There are blows in life, so powerful … I don’t know!” Those blows are “the black heralds sent to us by Death.” Somehow, through his rage, his self-pity, and his self-hate, Vallejo came to feel those blows as they landed on the heads of others. This compassion found its voice in his greatest work, the posthumously published “Human Poems” (1990). Amid the Spanish Civil War, where he learned that “pain grows in the world all the time,” the merely literary turned terrifyingly human. Now words that once dazzled and shocked would “wash the cripple’s foot,” or even more humbly, they would serve to “help my one-eyed neighbour sleep.”

eormsby@nysun.com