MOST NAZIS weren’t unduly bookish.Many of their leading lights were at best semi-literate cranks who, if they read anything at all, perused risible tomes about occultism and pseudo-scientific theories on racial purity.No sooner had the Nazis seized power than they began erecting large bonfires out of blacklisted works during their ceremonial book burnings, the idea for which they borrowed from Catholic inquisitors. Their goal was to cleanse themselves ritually of the pernicious influence of verboten ideas contained within these books’ pages. They would keep up the abhorrent practice for years.Nor was the movement’s foundational text a literary marvel. Adolf Hitler’s “Mein Kampf” amounts to an interminable stream-of-consciousness diatribe with turgid prose, the puerile outpourings of an obsessive monomaniac with bipolar disorder and messianic delusions. Another Nazi bestseller, chief party ideologue Alfred Rosenberg’s “The Myth of the Twentieth Century,” was worse still: a ponderous screed of quasi-mystical gibberish and historical revisionism that cast Jews as the congenital enemies of the “pure-blooded” Nordic master race. Even Hitler found it unreadable.True, Hitler himself was fairly well read and, as an avid bibliophile, possessed an impressive private library with several thousand books. Yet, the Führer mostly limited himself to fare that suited his purposes as wannabe master of the world: histories of famous military campaigns; books on politics, diplomacy and ersatz spirituality; and popular penny dreadful novels by his favorite German author Karl May, who wrote American westerns for adolescents.In short, we might assume that the Nazis generally didn’t care much for books – unlike valuable works of art, which they plundered rapaciously throughout occupied Europe.Not so. As the Swedish writer Anders Rydell makes clear in “The Book Thieves,” the Nazis, led by Rosenberg and SS chief Heinrich Himmler, meticulously stripped many of Europe’s finest and oldest libraries of their contents during the war. They ransacked the Sephardi libraries of Amsterdam, raided the Yiddish libraries of Vilnius and pillaged the Jewish libraries of Rome.They did so with a calculated aim: to hollow out the cultural heritage of the people they set out to destroy by robbing them not only of their lives but also of their collective memory and wisdom enshrined in ink on paper. Eradicating Jewish culture and literary influence, the Polish historian Marek Sroka posits, “became almost as important to the Germans as the physical extermination of the Jewish people.”The libraries of communists, freemasons and other perceived enemies of the regime weren’t spared, either. Nor were numerous libraries in occupied nations. In all, during the war, the Nazis contributed, in one way or another, to the destruction of millions of books, most of them in Eastern Europe. In German-occupied Poland alone, 90% of school and library book collections, as well as 80% of private collections, had been lost by the war’s end. Most of them had likely been seized or destroyed by the occupiers, while the rest perished in fires and bombing raids. The number of books thus lost in Poland amounted to a staggering 15 million volumes.Not only Jews but also ethnic Poles, whom the Germans deemed similarly “subhuman,” were subject to the wholesale theft of their artworks and books in an effort to reduce them to a collective state of cultural barbarism. Even schoolbooks and children’s books were systematically destroyed.“The stock of over 350 libraries was sent to paper mills for conversion into paper pulp,” Rydell explains.THE GERMANS also set fire to several historic libraries, including Poland’s National Library in Warsaw and the library of the Jewish Theological Seminary in Lublin. By doing so, they obliterated tens of thousands of invaluable and irreplaceable incunabula, religious texts, Torah scrolls, manuscripts, engravings and sheets of music. Seeing the contents of their Talmudic Academy’s library reduced to ash, the Jews of Lublin “cried bitterly,” one Nazi eyewitness recalled. “Their cries almost silenced us.Then we summoned the military band and the joyful shouts of the soldiers silenced the sound of the Jewish cries.”Meanwhile, in Amsterdam, Paris, Rome and elsewhere, the invading Germans similarly plundered and pillaged, ransacking private Jewish homes for their valuables, including books “down to the tiniest book- cases and scattered volumes on bedside tables,” Rydell notes. They did so even in the homes of the poorest Jews. Barbaric, yes. Yet, in a consistently edifying work of investigative journalism and popular history, originally published in Swedish in 2015, the author, who oversees the coverage of culture at a major Swedish media group, dispenses with the notion that the Nazis were no more than rampaging philistines – or, as he puts it, “unhinged destroyers of knowledge.” The Nazis certainly were that. But they also understood full well that knowledge was power. They knew better than to do away with their nation’s rich traditions of literature and culture – unlike Mao Zedong and Pol Pot, who would both try to refashion their societies from the ground up by eradicating whatever had come before.Rather, National Socialist ideologues sought to hijack some of Germany’s rich literary traditions for their own ends while sidelining or outlawing what they decried as “un-German” and “degenerate” streams of it. “In this war [for intellectual dominance], books would not be so much a casualty as a weapon,” writes Rydell, whose previous book, “The Looters,” dealt with the Nazis’ obsessive plundering of antiquities and artworks across Europe. “The Nazis wanted to defeat their enemies not only on the battlefield but also in thought.”Thus, the “Sturm und Drang” poet Friedrich Schiller was in; the pacifist Erich Maria Remarque was out. Especially loathed was the Jewish-born 19th-century poet Heinrich Heine, who famously observed that “where they burn books, they will in the end burn people.” He meant the Spanish Inquisition, but his words eerily foreshadowed the Nazis’ destruction of European Jewry.Even as the extermination of European Jewry proceeded apace, several educated Nazis were tasked with stockpiling Jewish books of diverse nature and provenance to study their contents. “In order to understand the spiritual weapons of our ideological enemies, it is necessary to go deeply into [their] writings,” explained the SS major general who headed an “ideological research” library set up for that purpose.BY STUDYING Jewish texts, Himmler and his exegetes hoped to gain mastery over Jewish ideas and beliefs, the better to purge any Jewish influence from German society once and for all. It was, in a way, an attempt at purgative mind control for the masses.The Nazi ideologues also wanted to find evidence of the global Jewish conspiracy detailed in the crude tzarist forgery “The Protocols of the Elders of Zion,” the urtext of modern antisemitism with its implausibly lurid self-incriminating admissions by the putative Jewish masters of the world.At the Institut zur Erforschung der Judenfrage, a research institution set up by the Nazis in Frankfurt to study the “Jewish Question,” a team of “Aryan” scholars sought to conduct, as they put it, “Jewish studies without Jews.” The professed aim of the institute, housed in the confiscated palatial residence of the Rothschild banking dynasty, was to uncover and document the nefarious activities of “world Jewry” for posterity, from alleged ritual murders to endless global conspiracies. It was an academic quest for perpetual scapegoating.“The Nazis strove to exterminate the Jewish people, but not their memory,” Rydell writes. “The Jew would be preserved as a historical and symbolic enemy.”To that end, the Nazis purloined any Jewish books they could lay their hands on.Soon after war broke out in September 1939 following the German invasion of Poland, six railroad cars arrived in Germany loaded with books seized from the Great Synagogue of Warsaw. Hundreds of other Jewish libraries in Poland, both private and public, would soon face a similar fate. The SS also kidnapped Jewish scholars, academics and intellectuals to help translate texts in Hebrew and Yiddish before they were murdered.In the Theresienstadt concentration camp, some 40 other Jewish scholars were pressed into the Talmudkommando (Talmud Unit) to sort through collections of pilfered Jewish books. The unit’s experts managed to catalogue a mere fraction of books at their disposal, so vast was the hoard amassed by the Nazis. At Frankfurt’s “Jewish Question” institute, another half million stolen tomes awaited sorting, but most remained in crates unpacked.In Vilnius, a historic hub of Jewish learning in Lithuania, the SS similarly pressganged several Jewish scholars into the so-called Paper Brigade to sift through loot from the city’s Jewish libraries and separate valuable volumes from less valuable ones.The former were taken by the SS for keeps; the latter were pulped.Ironically, even as Nazi ideologues set about destroying or confiscating certain books en masse, they kept pumping out others.Joseph Goebbels, an erstwhile journalist, was a wannabe novelist with a doctorate in philology and his Propaganda Ministry relentlessly promoted approved literary works. Throughout the 1930s, some 20,000 new titles were published annually, many in fancy, state-sponsored editions, as part of the regime’s ruthless Kulturkampf.As we know from history, such selective approval of literary merit was bound to end in failure over the long term. Yet, the Soviets had been enforcing equally repressive cultural controls, albeit along different ideological lines, so Hitler and his National Socialist ideologues certainly had an example upon which to draw. The Germans were a highly literate people who rightfully prided themselves on their nation’s rich cultural traditions, which the Nazis were now actively seeking to subvert for their virulent form of extreme nationalism.But what of the stolen books themselves? Unlike works of art, most books, being mass-produced artifacts, are rarely unique.They’re valuable only for their owners through emotional connections. Yet, those connections can be very strong. Rydell is a thoughtful man who discerns the countless personal tragedies of loss behind the Nazis’ wholesale plunder of private book collections and libraries.To the careless observer, old books with tattered spines and yellowing pages, now languishing largely uncatalogued and neglected in the depositories of libraries where pilfered collections had been stored since the war, may seem mere curiosities – forgotten relics from a bygone age of war and mass murder. To him, however, they are, singly and collectively, poignant mementos of lives and memories lost. Someone once owned and probably cherished many of these books. Often, they weren’t mere possessions but signposts in their owners’ emotional lives and intellectual development.One old book about Africa was given, as the penned dedication makes clear, to a Jewish boy in Berlin by his mother for his bar mitzva in 1930. The boy would grow into a young man who was deported to Riga in 1942 and murdered there – his dreams of traveling to Africa, if he still harbored those, dying with him. Another old book, a dogeared biography of Baruch Spinoza, belonged to a prominent German Jewish journalist, Ernst Feder. A collection of valuable antique almanacs, now kept in the Duchess Anne Amalia Library in Weimar, was owned by a well-off local Jewish businessman and lifelong bibliophile who was forced to sell them for a song before he was allowed to flee to Bolivia, where he died in penury.“Every book carries a story of theft, blackmail, and a tragic fate,” Rydell observes.“At best, it may be a story of flight, of bailing out on a life – but at worst a story of people who have left no trace behind except for these books.”IN ONE large public library in Berlin alone, well over 250,000 books have turned out on closer inspection to have come from libraries and homes looted by the Nazis during the war. Many books were marked “J” for Judenbücher – Jewish-owned books. A few dedicated librarians at Berlin’s Zentral- und Landesbibliothek (Central and Regional Library) are now trying to trace as many books as they can back to their original and likely long-dead owners. No easy task, that. A single book of unknown provenance in plundered collections can take weeks of painstaking sleuthing to trace to someone’s bookshelf in wartime Berlin, Paris, Vienna, Budapest or Prague. The resources dedicated to this project are meager and the libraries engaged in it are driven by a humanitarian impulse, not a legal obligation.Most books can never be traced as previous generations of librarians either carelessly or willfully disposed of dedications, stamps, bookplates and any identifying markings on flyleaves, spines and labels. Between 2009 and 2014, a mere 500 books, in the library’s collection of a quarter million plundered volumes, were returned to the descendants of their original owners. “These books are like ghosts in the library,” one librarian, Sebastian Finsterwalder, tells the author. “We know they are stolen, but from whom?” Yet, even a single book returned can brighten someone’s day – someone like an elderly Jewish man who survived the Bergen- Belsen concentration camp as a child and now lives in California. His daughter travelled all the way from the United States to Berlin to retrieve her father’s old book of Jewish fairytales for him. “He had nothing left of his childhood apart from a couple of photographs and the hat he wore in the concentration camp,” Finsterwalder explains.Thanks to the rediscovery of his beloved old book, the elderly man has finally opened up about his wartime experiences and begun telling children in schools about them.“These books are keepers of memories,” the librarian tells Rydell. “They are not worth much in a financial sense, but they can be priceless to the people and families who once owned them and then lost them.”“The Book Thieves” is a trenchant and, in parts, elegiac work. It, too, can now serve as a keeper of memory about what once there was and what was then lost in European Jewry’s greatest tragedy.