Matt Ridley’s The Rational Optimist, in glorious contrast, tells us what we really should want to hear: that the human species, through our unique ability to exchange ideas and thus innovate at the speed of thought, has overcome all the challenges that have ever confronted us, and will do so in future. Ridley’s particular contribution is to combine the insights of Adam Smith (how all benefit through trade and the specialisation of functions) with those of Darwin (how species evolve through breeding). Ridley calls this “ideas having sex” and the characteristic of the modern interconnected world is that ideas are having it away with each other with ever-increasing frequency: “The telephone had sex with the computer and spawned the internet.”