Few writers both reflect and influence American thought and culture. Malcolm Gladwell's work has done both in equal measure. As a New Yorker staff writer and as the author of The Tipping Point and blink--both seminal works on how and why humans behave the way they do--Gladwell's reach is unparalleled, his intellect maddeningly rich. The two books above, plus The Outliers and his most recent book, What the Dog Saw: and Other Adventures, retail in hardcover for a combined $108.  They are all signed by this preeminent social thinker of our generation, rendering it a truly unique and priceless addition to any serious personal or institutional library.