This set includes 4 different bookmarks that highlight some of the Great Thinkers of the past. A quote from each thinker is included on the back of each of the bookmarks. The featured Thinkers are: Ghandi, Abraham Lincoln, John Stuart Mill, and Thoreau. These make an excellent gift for the critical thinker in your life. Or perhaps you need a Thoreau bookmark to use when reading Walden? And your copy of On Liberty could use a John Stuart Mill bookmark.