More than 60 years after it devastated Europe, World War II does not inspire feelings of ambiguity or uncertainty in most of the children and grandchildren of those who fought and survived it. World War II – in contrast to Vietnam, Iraq, or even World War I – is remembered in the former Allied countries as the “good war,” the war we knew why we were fighting, the war that had a clear purpose, the war that achieved what it was supposed to achieve. World War II is fixed in the historical canon. Nothing about it seems vague or uncertain any more at all.

For those who actually lived through the war, the experience was far more confusing and certainly more morally ambiguous. Nowhere is this clearer than in the writings of Czeslaw Milosz (1911-2004), the Polish Nobel laureate who wrote some of the finest poetry about the war and its destructive aftermath in central Europe. Milosz, already an established writer by 1939, lived through the war in Warsaw, which experienced some of the most profound physical and psychological destruction. He wrote for the underground press, and witnessed both the Holocaust – the destruction of Warsaw’s Jews – and the Warsaw Uprising – the destruction of Warsaw’s intellectual and political leadership. He also witnessed the “victory” – a new occupation, by communists – and briefly collaborated with the new communist regime before defecting to the West in 1951.

Later in his life, Milosz came to be, if not reconciled to the war or its consequences, then at least able to write about other things, penning histories of Polish literature and translations of Whitman and Shakespeare. But in “Legends of Modernity” (Farrar, Straus & Giroux, 266 pages, $25),a newly translated collection of essays and letters he originally wrote in 1942-43 in Nazi-occupied Poland, he appears as one who is, understandably, obsessed by it. Although the book defies easy description, it is in some sense Milosz’s attempt to reconcile everything he knows about literature and humanity with the total destruction he was witnessing. Much of the book consists of essays dedicated to particular writers: Tolstoy, Balzac, Gide, Stendahl. But he uses his descriptions of their work to get to other subjects, whether the impact of total war on individual people (“War and Peace”) or the consequences of amorality (“The Red and the Black”), which were clearly relevant to life in occupied Poland.

At their deepest level, the essays reflect Milosz’s struggle to define and ultimately defend “civilization” – a term he uses to include religion, culture, and art – in light of all that is going on around him. Western civilization, he wrote, has led to “terrifying wars, exploitation and degradation” while also engendering the idea of “workers’ unions, insurance and universal education.” The same Western civilization has produced the lowest, most degrading forms of mass entertainment, as well as Dante and Shakespeare. He asks, rhetorically, whether it is possible to destroy one and not the other, and concludes in the negative:

Is it necessary to strike at the foundations of this civilization in order to uproot everything that encumbers it? Should what has grown up in organically and out of respect for man be replaced by a new Plato’s Republic? No.

Later, during an exchange of letters with another Polish writer, Jerzy Andrzejewski, he comes to the conclusion that in their era, an honest witness must concede that he has lived through both the “purification of mankind through suffering and blood, “as well as man being “worn down by cruelty.”

It’s hard to understand how an event like World War II can be both degrading and uplifting, just as it is hard to understand how Western civilization can be both exploitative and unifying, producing both schlock and high culture. Milosz felt the importance of the effort, that the foundations of that civilization are worth defending, however difficult a task it may be. And the defense itself, in a time of terrible tragedy, has some value: “I strongly believe,” he wrote, “that there are epochs … to whom it is granted to come very close to the mystery of man, to look him right in the eye.” If that is true, then Milosz was clearly living in one of them.

Ms. Applebaum, a member of the Washington Post’s editorial board, is the author of “Gulag: A History,” The New York Sun’s Book of the Year in 2003.