Why do westerners have so much cargo? That is the question, asked by a New Guinea tribesman, that motivated the author to pull together a lifetime of insight in this explanation of the march of human history. The title captures the main themes.The book earned a Pulitzer Prize and long print runs for its author, and for good reason. Insights emerge from seed distribution studies, linguistic analysis, conquistadors, the Polynesian Diaspora, food production, the wheel, and many other places. The author’s intellectual scaffolding carries the natural history of mankind on its substantial framework, and it is tightly argued and convincing in most respects (at least for a lay reader such as myself). Many of the ideas in this book are controversial. Beliefs about cultural success and dominance are commonplace and difficult to resist, particularly in this moment of seemingly unending clashes of civilizations. This book provides a framework within which to understand the gifts that geography, climate, and microbiology confer on the development of civilizations, setting aside arguments of who is better or smarter.My Seattle housemate observes that only science can ask questions of God, as science alone confers a methodology of judging answers without risk of self deception. This is true only for science that aspires to prediction rather than explanation, however. Facts are far less malleable in face of an experimental result than within the comfortable argument of a post-facto explanation. At times, though, Diamond evokes particularly sharp focus, as with the natural experiment of the Maori-Moriori collision in the Chatham Islands. Even a liberal might look a second time at questions of defense spending.It is in the postulation of refutable facts that science gives us confidence. Explanatory ‘science,’ wherein falls Diamond’s efforts, can never convince as reliably. Nonetheless, within the intersection of the melding points of societies and the melting points of alloys, Diamond creates a rigorous, fascinating, and convincing story of cultural destinies that sheds light and enlightenment. But yikes… 30 pages of acknowledgements? Thank heaven they came at the end.