Eighty years ago on Friday, and only months after Adolf Hitler's rise to power, his Nazi followers burnt piles of books in what has been labelled the nation's "intellectual decapitation" -- an act of terror that foreshadowed worse to come.
A metal plate in the grounds of Berlin's Bebel Square, where 20,000 books went up in flames, is covered in dust from nearby renovations, but the chilling quote from 19th-century poet Heinrich Heine stands out: "Where they burn books, they will also burn people."
It was here, outside the city's opera house and Humboldt University library, where shortly before midnight on May 10, 1933 Nazi student groups torched the works of Sigmund Freud, Heinrich Mann, Karl Marx, Kurt Tucholsky and other thinkers and literary giants. It was the first dark milestone in the Nazis' purge of what they deemed "undesirable and harmful literature" with an "un-German spirit" and ushered in the systematic, deadly persecution of Jewish, Marxist and pacifist writers.
The goal of the students, radicalized by chauvinism, was to eradicate the "decomposing Jewish spirit" and promote "national consciousness". The fiery spectacle, which was mirrored in 20 other German cities, is now commemorated in a subterranean space on Bebel Square under a glass lid, occasionally stepped on by tourists. A gaze downward reveals a basement library with empty shelves.
It is the creation of Israeli artist Micha Ullman and recalls how Nazi student groups intended to rip out the literary heart of a nation that thought of itself as "the land of poets and thinkers."
"The works of around 400 authors went up in flames, including the creme of the literary, scientific and intellectual community of the Weimar Republic," Germany's post-World War I government, said Free University of Berlin literature professor Irmela von der Luehe. In the words of sociologist Helge Pross, the spectacle spelled the "intellectual decapitation of Germany".
In a carefully-staged ritual, said von der Luehe, they "lit fires, books were delivered on carts, to the beating of drums". As the Nazis hurled the books into the bonfires, they delivered scripted "fire spells" that were identical throughout the country.
The fanatical students had signaled the book burnings in an article published in Bonn on May 8, 1933 in which they declared their aim: "We are fighting for the purity of our culture." It followed a boycott of Jewish shops on April 1. Many of the authors on the list had already fled Germany, driven into exile shortly after Hitler's accession to the chancellery on January 30, 1933.
The book burnings, however, "caused an incredible terror among those who had already settled in Paris, Vienna, Prague or Switzerland", said von der Luehe. "From this moment on, no-one had any illusions."
A little over five years later, it was the synagogues that burnt during the so-called Night of Broken Glass.
The "Final Solution" -- the Nazi plan to eliminate Jewish people -- ultimately claimed the lives of millions.
"Heinrich Heine's verse was already in the minds of all these authors," said the researcher von der Luehe. Erich Kaestner, father of classic youth book "Emil and the Detectives", chose to stay in Germany, adopting the path of "inner emigration" or passive resistance, which he described with the words "We are a living corpse."
Others reacted in a more extreme way. Austrian novelist Stefan Zweig committed suicide in February 1942 in Brazilian exile.
Scientists, architects, university professors -- "all the scientific excellence that before 1933 brought Germany its many Nobel Prizes" -- escaped Germany, said historian Werner Tress of the Centre for European-Jewish Studies in Potsdam. "Since then, it has never managed to recover the rank it held before 1933."