Book burning has been used as a terroristic threat, a symbol of power, and a cultural cleansing since ancient times. In ancient times, when many books were the only copy in existence, book burning was often a sign of conquest. The conquering nation would destroy the accumulated knowledge of a conquered land in order to install their own culture. Destroying cultural knowledge became more difficult after the invention of the printing press, but book burning continued, as a symbol of preferred thought if nothing else. It was often a demonstration of crushing a dissention.
The unifying factor between all types of purposeful book-burners in the 20th century, Knuth says, is that the perpetrators feel like victims, even if they’re the ones in power. Perhaps the most infamous book burnings were those staged by Adolf Hitler and the Nazis, who regularly employed language framing themselves as the victims of Jews. Similarly, when Mao Zedong took power in China and implemented the Cultural Revolution, any book that didn’t conform to party propaganda, like those promoting capitalism or other dangerous ideas, were destroyed. More recently, the Jaffna Public Library of Sri Lanka—home to nearly 100,000 rare books of Tamil history and literature—was burned by Sinhalese Buddhists. The Sinhalese felt their Buddhist beliefs were under threat by the Hinduism of Tamils, even though they outnumbered the Tamils.
Even when the knowledge itself isn’t prevented from reaching the public, the symbolic weight of burning books is heavy. “Books are not absolutely dead things, but do contain a potency of life in them as to be as active as that soul was whose progeny they are,” wrote John Milton, author of Paradise Lost, in his 1644 book Areopagitica. “Who kills a man kills a reasonable creature… but he who destroys a good book, kills reason itself—” an idea that continues to be espoused in modern culture, like in Ray Bradbury’s Fahrenheit 451.
Read accounts of book burning and its evolving purpose at Smithsonian.