From http://www.nonzero.org/ The title of this book, Nonzero, refers to the concept of the "non-zero-sum," which comes from game theory. Looking at human history--and for that matter the whole history of life on earth--through the lenses of game theory can change your view of life. At least, that is a premise of this book. What exactly is meant by "change your view of life"? That is a question with a book-length answer. But there is enough material on this website to give you the general idea. Meanwhile, some examples of non-zero-sum things: arms control negotiations, trading gossip, the relationship among genes on a genome, and such transactions as buying a car, buying a book, buying a book or, finally, buying a book.