I read John Horgan's The End of War a few month ago now, but I haven't gotten around to saying much about it. Part of the problem is that I don't know what to think. It's a small book which manages to wander in many different directions, and the primary focus is Horgan's mantra that war is not an inevitable fact of the human condition. Since I agree with that proposition much of the argumentation was lost on me. And yet there is one aspect of the book which was notable: a disputation of the Richard Wrangham's work in Demonic Males. I'm still quite a fan of Wrangham's thesis, but over the years I've become much more skeptical of one of the primary methods he employs: extrapolation from another ape (in his case, chimpanzees). Similarly, I'm also skeptical of those who claim that we're more more like bonobos (here's looking at you Frans de Waal). No, we're human beings, and our common ancestor with other apes may have been very different from all the descendant lineages. Our cousins are informative and interesting, but we shouldn't confuse ourselves for our cousins. Horgan's book could have benefited from conceptual clarity. It is true that thinkers in the past have believed that slavery or gross poverty were simple facts of the human condition. Today slavery is banned de jure in every locality across the world, and has been predominantly extirpated de facto. Why? Inevitable forces of social and economic history I'd say, which give succor to ideological movements. I think a similar process occurred ~3,000 years ago, as practices like human sacrifice were abandoned across the civilized societies of Eurasia. Similarly, in particular material and historical conditions slavery is inevitable, and a fact of human life. Just as there is not a gene for slavery, or worshiping god-kings, or building pyramidal structures, these cultural features have emerged independently across human societies. The most plausible explanation for these parallelisms is that the basic evolutionary psychological raw material of humans (which is relatively similar across societies) interacts with specific material conditions (which may also be relatively similar across societies). It turns out, for example, that a god-king is an excellent cultural institution for maintaining political coherency. And, it seems to co-opt and tap into deep human psychological preferences and biases. This does not mean that god-kings are inevitable features of human existence. Rather, they're highly likely in very specific conditions. And so it is with war. Horgan concedes that the relative universality of war over thousands of years suggests that its emergence was not coincidental or random. But it also seems that the prevalence of inter-state conflict is declining, and there are broader social and economic forces which scaffold this dynamic. The idea that organized warfare is not a biological imperative is a fine one to tackle, but The End of War could have benefited from less exhortation and more concrete plan of action. Addendum: I highly recommend Azar Gat's War in Human Civilization.