There are endless riffs on story shape – sometimes subtle, sometimes brutal explorations and excavations of an original tune. Often you may have to search long and hard to find it, but the tune – even in its absence – will be there. In music, poetry, film – arguably all art – digression merely confirms the archetype’s importance.

This kind of story sits deeper than any piece of literature or propaganda, deeper than our epic myths or religious texts. It operates at the level of world-shaping that Donella Meadows, one of the pioneers of systems thinking, articulated as the paradigm, which she described as: ‘The shared idea in the minds of society, the great big unstated assum