On October 17th 2024, I published an article on the Institute of Art and Ideas blog site called 'Why maths alone cannot predict the economy: Mathematical proof is not economic factLink opens in a new window'. It provides a brief philosophical account of the main claims of my recent book, False Prophets of Economics ImperialismLink opens in a new window. The most sophisticated proof-makers in mathematical economics, I argue, were clear right from the outset of their endeavour that they were not talking about the world as it is actually experienced. They were engaged instead in creating epistemic artefacts that could act as the spur to further thinking, but only on the realisation that the world that appeared in their models was a parallel universe to the world in which everyday life is lived. In other words, they were conducting thought experiments, primarily about what might go wrong if the market systems represented by series of equations were treated as something more than the mathematical notation of which they are comprised. Contemporary practices of economics imperialism fall into precisely this trap. They have to first pretend that complexly layered social situations are really markets at heart, before they can then use their mathematical market models to define the essence of those environments. As I show, though, there is no philosophical justification for proceeding in such a way. The whole project of economics imperialism thus falls down.