Libraries have existed for nearly as long as humans have had written languages. They have been esteemed places of learning and comprehensive repositories(储藏室) of human knowledge, history, and ideas. Written materials from all over the civilized world have been collected and preserved in libraries, and without them much of what was known to ancient peoples would have been lost in the modern world.
Democracies and open societies, especially like the free exchange of ideas and information—all ideas, not just those that are socially acceptable at a particular point in time and all opinions, no just mainstream ones.
Our public libraries need to be places that broaden our perspectives and stretch our minds and imaginations. There's no reason to ban any books from the general public. That's not to say all books are appropriate for all age groups. But it's easy enough to limit access of the very young to "adult" literature without preventing mature readers from a full range of materials.
Private libraries may sometimes regard certain topics as too offensive or objectionable to include in their collection. And elementary school libraries should probably not include books that would be inappropriate for young children on their bookshelves. All libraries have to be selective, due to limited budgets, and space and age are always considered in acquisition decisions. But this is very different from actually banning specific titles.
And who is to decide what is acceptable and what is not? Should we get rid of all materials that are unconventional, that challenge the present situation, or that make anyone uncomfortable? Should we restrict all materials in public libraries to what is inoffensive to the most sensitive members of society or to what overprotective parents believe will not disturb young children?
Democracies, as they say, are messy. The Harry Potter novels may be the greatest children's books ever written. Howard Zinn's A People's History of the United States may be a publication of nation's rich history, but sometimes brutal history to some else, especially those ever hurt by the country. Anyway, libraries exist to preserve all human thoughts and recorded experience.
