Years after the 2008 crisis, and no-one in the banks has been held accountable. Not even for negligence! It is difficult to disentangle guilty ingredients from the hot financial stew, but much more so without an organized political will. Without better institutions (nomos) our deepening knowledge of the world (cosmos) will continue to fall flat . . . The problem of better institutions, it so happens, is linked to that of better models, since these models provide impetus and fodder. Quantitative models don’t just measure but also create phenomena: in Donald McKenzie’s words, they are engines and not cameras. A digression into the models of finance and their philosophical grounds is, I hope, useful here. Elie Ayache in Blank Swan has put forward a thorough rebuttal of not just the possibility of prediction, but possibility in general.