Notes on an unpublished article by Paul Lockhart titled, "A Mathematician's Lament". It was later published on the Devlin's Angle website under Lockhart's Lament and followed by a post two months later that focused on critic of the article and a response from the author (see Lockhart's Lament - The Sequel). In 2009 the 25-page article was expanded into a 140-page book.