After, so because

Post hoc treats one thing coming after another as proof that the first caused the second. A timetable change, then a drop in sales. Hot weeks, then both ice cream and drownings. Order is a clue. It is not, by itself, the cause. Ask what else moved at the same time, and what would count against the story. The card does not say causes are unknowable. It says a single sequence is not yet a reason. News copy often stops at the sequence because the sequence is easy to tell.

Fallacy

Post hoc

Post hoc ergo propter hoc treats “after this” as “because of this.” Order in time is necessary for a cause of that kind, but it is not sufficient. Other changes may explain the result.

Open the full card

Mini check

"After the town changed the bus timetable, the bakery's sales fell. So the timetable change caused the drop." What is missing?

Something more than one thing coming after another.A famous person who likes the bakery, and nothing further.A blanket claim that bakeries as such are always good.A personal attack on the mayor, unrelated to the sales.

Weeks with high ice-cream sales also have more drownings. What is the most likely explanation?

Hot weather drives both: more ice cream and more swimming.Eating ice cream makes people more likely to drown.Drownings make people buy ice cream to cope.The link must be a printing error, because it makes no sense.

Try it today

Find one 'after this, therefore because of this' sentence and name another possible cause.

Next step