In his book Poetics of Cinema, Raúl Ruiz recalls a moment in his youth in Chile when he “began thinking about so-called dramatic construction”. He consulted an American textbook by John Howard Lawson (which he refers to as How to Write a Script, but is most likely Theory and Technique of Playwriting and Screenwriting) and discovered there something that was (and still is) called central conflict theory: the “law” (as Lawson calls it) that all stories must be based on a conflict, usually between two characters, with a hero wanting something and a villain trying to stop him from getting it. “Then, I was eighteen”, writes Ruiz. “Now I’m 52. My astonishment is as young now as I was then. I have never understood why every plot should need a central conflict as its backbone”.

Ruiz's bewilderment is understandable. The central conflict theory – if you look at it askance – is indeed a weird, almost perverse theory, although this perversity masquerades as perfect, commonsense normality (as most dangerous ideas usually do). It is a violent theory. And it is a very American theory. But it is a theory whose day has definitely come on the international stage.

Ruiz remarks that, 30 or 40 years ago, central conflict theory “was used by the American mainstream industry as a guideline. Now it is the law in the most important centres of film industry in the world”.