"In this piece, Pinker appears to me to change sides almsot completely, from pessimist to optimist and from genetic determinist to social improver. Not only does he present evidence that war and violence are declining in relative importance, his explanation for this seems to be entirely consistent with the Standard Social Science Model he caricatured and debunked in The Blank Slate. He’s still got a sort of rational self-interest model in there, but now Hobbes is invoked, not for his ‘nasty, brutish and short’ state of nature, but for his argument that the Leviathan of social order will suppress violence to the benefit of all."