A field guide to the ways reasoning breaks
Causal errors
Also called After this, therefore because of this
Treating sequence as causation, so whatever came first is taken to have caused what followed.
Sales rose after the rebrand, so the rebrand caused it.
Ask what else changed in the same period, and what sales did before.
From the Latin 'post hoc ergo propter hoc', 'after this, therefore because of this'. The phrase fossilizes one of the oldest mistakes in reasoning: letting the calendar stand in for a mechanism. It is the template from which most causal fallacies are cut.
Ever since we switched to the new coffee supplier, people have been calling in sick less. Good call on the coffee.
I updated my phone and now the battery drains fast — the update broke it.
The city's accident rate dropped the month the new mayor took office; his leadership is clearly working.
Two days after I started the herbal supplements, my headaches stopped. They work.