This week, we have a guest on the show - Rodrigo Aguilera. Rodrigo is an economist - born in Mexico, lives in London, and his writing has appeared all over the place in various forms over the years. Specifically, we're talking to him about his book "The Glass Half-Empty: Debunking the Myth of Progress in the 21st Century". Now; this may sound like a rather gloomy take to pick, but the point that he is making is essentially that we shouldn't be happy with a narrow and limited definition of "progress" when we have the capacity to achieve so much more. But, of course, if we genuinely do want to see progress: if we want to see things like the elimination of poverty, the application of human ingenuity and compassion and rationality and empathy towards solving the problems that exist in the world - if, in other words, we actually want things to get better, rather than just complacently gesturing at lines on graphs which tell us things are getting better - this must begin with an accurate assessment of where we actually are, right now; what has led to progress in the past; and how we can get further in the future.

Rodrigo was incredibly generous with his time, and so I've split the resulting interview into two parts: you're about to hear the first one, where we will talk about what the "New Optimism" theory is; I hope you enjoy it.