Affirming the consequent
Also called: Converse error
Reasoning “if A then B; B is true; so A is true”, when B could have other causes.
How to spot it
A rule that runs one way is used backwards.
Example
“If it rained, the road is wet. The road is wet, so it rained.” (A burst pipe, a street cleaner or a sprinkler would do as well.)
How to answer it
Name another way B could have happened. B alone doesn't settle that A did.
Related
- Post hoc: Assuming that because one thing followed another, the first caused the second.
- Reverse causation: Assuming A causes B when B actually causes A.
- Non sequitur: A conclusion that doesn't follow from the reasons given, even if the reasons are true.