Telling a Cause From a Coincidence
Two things moving together is not one causing the other. Test a causal claim about the past by checking the order of events, hunting for a third factor that could explain both, and asking what evidence would count against the claim.
What a learner can do afterwards
- Give a case where two historical trends moved together without either causing the other
- Check that a proposed cause actually came before the effect it is offered for
- Name a third factor that could explain both of two linked changes
- Say what evidence would count against a causal claim you have just made
1 · Read
Two things moving together is not one causing the other. Correlation means they rise and fall as a pair, while cause means one brings the other about through a path you can name. When you read that one event caused another, your first job is to refuse the shortcut.
Run two checks before you believe any causal claim. First the order check: the proposed cause must come before the effect, so if banks spread after mills were built, banks did not start the mills. Then the mechanism check: coal could power steam that ran machines, and that chain holds because each link touches the next.
Plague deaths and wage rises moved together in the 1300s, but germs did not sign pay deals. Fewer workers meant lords competed for hands, and that bargaining lifted pay. Labour shortage is the third factor here: one change explaining both halves at once. Ice cream sales and drownings work the same way, with summer heat driving both.
Always ask what evidence would count against your own claim. A find showing the effect came first, or a link in your chain failing its test, should sink it. If no possible find could shake you, you are preaching, not reasoning, and good historians hunt the proof that could prove them wrong.
Check order, name the path, hunt the third factor, and state what would prove you wrong.
2 · Watch
Take it off screen
Where it sits
Where this leads
Jobs that lean on this skill. Follow one to see everything it is built on.
8 questions wait behind this lesson, each with its answer explained. Every answer feeds the sky: stars light as they are learned, and dim when it is time to come back.