Robert A. Dahl

Ironically, the very fact that democracy has such a lengthy history has actually contributed to confusion and disagreement, for 'democracy' has meant different things to different people at different times and places.

Many of Judy Blume's books - which I devoured when I was growing up and where I found characters that were believable because they were a lot like me - caused considerable consternation when they were first published, but now they're widely accepted as an essential part of the children's literary canon.