Diamond boils it down to four key issues: the availability of plants and animals to be domesticated, the ease with which this domestication can be transferred (east-west being easier than north-south due to similar climates), isolation, and the size of the population. What we call western civilization emerged in the fertile soil of southwestern Asia, with a host of available plants and animals for domestication. It then spread rapidly along the east-west axis of Eurasia. This reliance on farming made a dense population possible, which along with the proximity of the domesticated animals led to a host of endemic diseases. These diseases, when brought to the Americas, did more to subjugate the natives than either the guns or the steel of the title.

This thesis is explained in detail, first in overview and then with the quick example of the Polynesian islands. Part two of the book covers food production and the domestication of animals. Part three expands by covering the increase in disease and the spread of writing and technology based on the previous principles. And the final part provides a quick investigation of five parts of the world that demonstrate how geography affected their inhabitation and culture.

It's a powerful and persuasive thesis, though Diamond admits that further investigation is needed.

His prose is straightforward if somewhat rhetorical. He hews very closely to the advice that a writer should tell you what he's going to tell you, tell you, then tell you what he's told you. He's also quite fond of rhetorical questions, though this seems a useful device in this context.

Overall, it's a fascinating and thought-provoking book, and includes an extension section on recommended further reading--all of which sound very interesting as well!

On page 87, the chart entitled "Factors Underlying the Broadest Pattern of History" outlines Diamond's entire case. Due to weather patterns, continental shape, and topographical variation, the band of cultures arranged along the Eastwest axis from Portugal to Vietnam had a superior starting point compared to those cultures stretching Northsouth from Alaska to Chile or from the Sudan to South Africa.

As humans evolved from hunter-gatherers to farmers, food surpluses enabled for the first time a segment of society to do something other than scrounge for their next protein hit. Increases in food storage and food production enabled ever greater specialization: "stored food can also feed priests, who provide religious justification for wars of conquest; artisans such as metal workers, who develop swords, guns and other technologies and scribes, who preserve far more information than can be remembered accurately." New technologies are produced by this thinking-inventing class; both by trial and error and by sustained experimentation, new methods, inventions, processes, weapons, and philosophies are brought forth into the world.

By showing that innovations occur, independently, in every race and culture -- "the myriad factors affecting innovativeness make the historian's task paradoxically easier, by converting societal variation in innovativeness into essentially a random variable" - Diamond is able to sidestep charges, should one be so inclined (and many ones are inclined so) of racial determinism.

So in each of these areas, as societies independently produce innovations in guns, germs or steel, they share or trade them with their neighbors. For the Eastwesters, this is easy because the climate from Portugal to Vietnam is rather similar, broadly speaking. For the Northsoutherners, however, the crops and mammals that thrive in the American plains or the Andes wither in the Guatemalan heat and vice versa. Therefore, trade and the exchange of ideas are hampered.

And thus, geography is destiny.

The wheel, invented by the Eastwest crew in 3,000 BC diffuses rapidly within a few centuries. Invented independently in prehistoric Mexico, it never makes it to the Andes (Diamond cites the throttling power of the narrow Panama isthmus, though I wonder why does a narrow landmass throttle diffusion and not accelerate it?) In another example, writing zips rapidly across Eurasia while it languishes with the Mayas in the Americas.

Similarly, with food: "of the world's 148 big wild terrestrial herbivore mammals - the candidates for domestication - only 14 passed the test. Why did the other 134 species fail?" Eurasia ends up with 13 of them, the Americas 1, sub-Saharan Africa and Australia - zero

And as a result of food - disease. Eurasian crowd diseases evolved out of the diseases of Eurasian herd animals. And a lack of these mammals in the New World led to a paucity of disease (the author includes an interesting sidenote on why llamas are not a source of human disease). Most wars prior to World War II were won by the side spreading nastier germs (a novel and not entirely convincing argument - were the Mongols, with their small core of Mongolians surrounding by an ever-expanding army of conscripts, really able to direct their germs at the enemy and not their own troops?) And European diseases eliminated 95 percent of the pre-Columbian population of the Americas within two centuries of arrival.

So geography is destiny and in the area of invention, food, and disease, Eastwest orientation is superior to Northsouth.

Even within Eastwest, we find geography has implications:

"Europe has a highly indented coastline with five large peninsulas that approach islands in their isolation [and thus] Europe is carved up into independent linguistic, ethnic and political units by high mountains"

While "China's coastline is much smoother" with no bifurcating ranges separating tribes and generating animosities, dialects, separate ethnic identities, or, importantly, sharable innovation.

Call this Diamond's Contiguous China theory: Europe's disunity leads to experimentation (Columbus asks five different regents to support his voyages before one will support him) while the Chinese monolith ends its voyages of discovery in 1421 due to court intrigue.

Perhaps Diamond's Contiguous China theory has implications for writing systems as well. Writing always starts as pictographs. In the Mediterranean, these symbols, forced into contact with many different pronunciations, syllables, diphthong and accents lost all but their most basic phonemic essence. "Alphabets apparently arose only once" in Syria and were then borrowed, copied, co-opted and diffused throughout the Eastwest axis. While Chinese characters, which gradually expanded along with the monolithic linguistic-political area (even though ultimately that monolith sprouts wholly different languages, the process is gradual enough to not rupture the writing system in the interim) had no such stripping away. And thus Chinese has several thousand characters, each idiosyncratically replete with meaning; while the few dozen Western characters are meaningless of themselves and merely phonemic.

Perhaps the best evidence of Diamond's deftness of touch is the complete absence of opprobrium for the author since publication of what is after all, an explanation of why Europeans and Asians succeeded and Africans and Native Americans didn't. Even rational, dispassionate treatises on topics tangentially touching race tend to produce a singular level of venom and vitriol from the shouting classes. Diamond so smoothly handles these sensitive issues, head on, that there is simply no race-baiting angle from which to attack him.

Indeed, the differences in outcome are attributed not to race, ethnicity, genes, culture or any other factor inherent to these groups at all, but rather surprisingly and benignly, to the geographical orientation of one's neighbors! A more arbitrary, non-threatening explanation for observed differences in national success would be difficult to conceive. And for that, the modern, liberally minded student, the originality, rigor, scope and truth of Diamond's thesis is all the sweeter.

This is a rare work in that it can appeal to academics and pleasure readers. The knowledge and research behind the concepts in the book are complex and detailed, but Diamond does such an excellent job of explaining things, that you can easily sometimes forget the vast amount of information that he had to assimilate in order to put forth this hypothesis.

There are also two main points from the book that I took. One is the merely academic and scientific data that you learn from the book. I do not have a science, anthropologic, or linguistic background, so I learned a great deal from this book. But secondly, there is a very clear goal of this book to discount the foundations of racism. This is a lesson that every reader from this book can take with them and actually use in real life. I was struck at how this book can have such a dual purpose, and this makes it truly unique in my opinion.

Sure, there are vast generalizations that are made in a work such as this, just as there are in any history book, but this book has excellent points, is well researched, and makes solid arguments. I would definitely read another book by Jared Diamond and will definitely not forget the lessons I learned in this book.