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Concept of the Week · Episode 5
A philosopher's way of saying that causes are almost always tangled. An INUS condition is an Insufficient but Necessary part of a set of conditions that is itself Unnecessary but Sufficient for the result. The spark alone did not cause the fire, and the fire could have started another way.
Explained by Professor Peter Kinderman, clinical psychologist · First published 18 August 2026 · Updated 21 October 2026
J.L. Mackie, in his 1965 paper Causes and Conditions and later in The Cement of the Universe.
INUS, from the philosopher J.L. Mackie, which is a formal way of saying that causes are almost always more tangled than they look. A fire needs a spark, but the spark could have been a match, a lighter or a dropped cigarette, and no single one of them is the whole story. It is a useful lens for everything from why a wildfire took hold to why the far right gains ground: there is rarely one simple cause, however much a headline wants there to be.
Episode five started with the emergency alert and the wildfire risk behind it, then moved to public shaming and the death of Professor Jason Arday. INUS is the lens for both. A fire needs a spark, but the spark could have been a match, a lighter or a dropped cigarette, and no single one of them is the whole story. The same goes for why a pile-on takes hold or why the far right gains ground: there is rarely one simple cause, however much a headline wants there to be.
Hear it in context
Public shaming, an eclipse and Count Binface
Public shaming and the Arday tragedy, the awe of an eclipse, and Farage versus a bin, tied together by one idea: it is always more complicated than the headline.
Insufficient, Necessary, Unnecessary, Sufficient. The match was insufficient on its own (it needed dry grass and wind), necessary within that particular set of circumstances, and that whole set was unnecessary (another set would also have done it) but sufficient once it came together.
Because headlines are built to name one cause, and the world does not work that way. Asking what else had to be true for this to happen is the fastest route out of a lazy explanation, and it pairs with the episode's Triple T: wait a second before you respond.
The primary literature behind the idea, for anyone who wants to check it. Also on Wikipedia.
Kinderman, P. (2026). INUS conditions. Concept of the Week, Experience: Analysing Newsmakers, episode 5, with Hilary Jeffs. https://www.experiencepodco.com/concepts/inus-conditions.html
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Concept of the Week is a regular feature of Experience: Analysing Newsmakers, the weekly podcast in which clinical psychologist Professor Peter Kinderman and communications expert Hilary Jeffs take the news apart to see what is driving it. Peter picks a psychological idea most of us have half-remembered wrong and explains what it actually shows. New episodes every Tuesday. Where to listen.