CF Dictionary · Evaluating Ideas & Arguments
Counter-Example
A single instance that contradicts a universal claim — the workhorse decisive criticism.
A counter-example is a specific instance that contradicts a universal or general claim. "All ravens are black" is refuted by exhibiting a single white raven. The single instance is the entire refutation.
Why counter-examples are central to CF
Counter-examples are the canonical decisive criticism — they're:
- Common. Almost every universal claim is vulnerable.
- Easy to grasp. A specific instance beats a statistical claim.
- Logical. They use only universal-premise reasoning.
- Fallible but effective. If you accept that you've correctly identified the counter-example, the universal is refuted; if your identification is wrong, the universal stands.
The asymmetry, again
The reason counter-examples work for refutation but confirmation doesn't is the asymmetry:
- 1 counter-example → refutes the universal.
- 1,000,000 confirming instances → does not confirm the universal.
CR calls this "the logical asymmetry between verification and falsification." CF builds Yes or No Philosophy on top of it.
"Despite all those merits, there could still be an error that causes failure. Basically, errors have logical priority over positive traits." — criticalfallibilism.com