The idea that a new world can be constructed through the rational application of force is peculiarly modern, animating ideas of revolutionary war and pedagogic terror that feature in an influential tradition of radical Enlightenment thinking. Downplaying this tradition is extremely important for Pinker. Along with liberal humanists everywhere, he regards the core of the Enlightenment as a commitment to rationality. The fact that prominent Enlightenment figures have favoured violence as an instrument of social transformation is—to put it mildly—inconvenient.Say Mao, for example. To Pinker's assertion that 'we take it for granted that war happens in backward parts of the world,' Gray notes that this requires us to think of the entirety of Asia, post 1945, as backwards.
It's a pretty humbling and intense criticism, which is exactly what the argument merits.