I It looks like liberal democracy is falling apart. But we can put it back together if we take democracy seriously enough—as seriously as the ancient Greeks. The chaos of Donald Trump was unimaginable just a decade ago. Brexit was a similar humiliation for Britain’s political class, leading to its bewildered paralysis ever since. How do such things happen? Perhaps because I admire economists’ deployment of very simple ideas to powerful effect, I’ve come to an approach to these problems that I think is simple and compelling. First, democracy is government by conversation. A political conversation should often be competitive—to sharpen ideas and measure their support. Yet, to remain a conversation rather than a parody of one, it must also be a co-operative search, if not for agreement, then at least for mutual understanding of where positions differ. However, this co-operative foundation for our politics has been largely extinguished by the weaponisation of political communication by professionals operating on the mass media, and, more recently by “trolling” on social media. Second, where elections bake competition …