“The history of interactions among disparate peoples is what shaped the modern world through conquest, epidemics and genocide. Those collisions created reverberations that have still not died down after many centuries, and that are actively continuing in some of the world's most troubled areas.”

“It seems logical to suppose that history's pattern reflects innate differences among people themselves. Of course, we're taught that it's not polite to say so in public. We see in our daily lives that some of the conquered peoples continue to form an underclass, centuries after the conquests or slave imports took place. We're told that this too is to be attributed not to any biological shortcomings but to social disadvantages and limited opportunities.Nevertheless, we have to wonder. We keep seeing all those glaring, persistent differences in peoples' status. We're assured that the seemingly transparent biological explanation for the world's inequalities as of A.D. 1500 is wrong, but we're not told what the correct explanation is. Until we have some convincing, detailed, agreed-upon explanation for the broad pattern of history, most people will continue to suspect that the racist biological explanation is correct after all. That seems to me the strongest argument for writing this book.”

“It's striking that Native Americans evolved no devastating epidemic diseases to give to Europeans in return for the many devastating epidemic diseases that Indians received from the Old World.”

“History followed different courses for different peoples because of differences among peoples' environments, not because of biological differences among peoples themselves”

“People often ask, "What is the single most important environmental population problem facing the world today?" A flip answer would be, "The single most important problem is our misguided focus on identifying the single most important problem!”

“Globalization makes it impossible for modern societies to collapse in isolation, as did Easter Island and the Greenland Norse in the past. Any society in turmoil today, no matter how remote ... can cause trouble for prosperous societies on other continents and is also subject to their influence (whether helpful or destabilizing). For the first time in history, we face the risk of a global decline. But we also are the first to enjoy the opportunity of learning quickly from developments in societies anywhere else in the world today, and from what has unfolded in societies at any time in the past. That's why I wrote this book.”

“Isn't language loss a good thing, because fewer languages mean easier communication among the world's people? Perhaps, but it's a bad thing in other respects. Languages differ in structure and vocabulary, in how they express causation and feelings and personal responsibility, hence in how they shape our thoughts. There's no single purpose "best" language; instead, different languages are better suited for different purposes. For instance, it may not have been an accident that Plato and Aristotle wrote in Greek, while Kant wrote in German. The grammatical particles of those two languages, plus their ease in forming compound words, may have helped make them the preeminent languages of western philosophy. Another example, familiar to all of us who studied Latin, is that highly inflected languages (ones in which word endings suffice to indicate sentence structure) can use variations of word order to convey nuances impossible with English. Our English word order is severely constrained by having to serve as the main clue to sentence structure. If English becomes a world language, that won't be because English was necessarily the best language for diplomacy.”