- If P, then Q.
- Not P.
- Therefore, not Q
This fallacy is often confused for the valid argument Modus Tollens which has the following structure:
- If P, Then Q.
- Not Q.
- Therefore, not P.
The comedy show It's Always Sunny in Philadelphia presents an excellent example of Denying or Negating the Antecedent in the following clip:
If we reconstruct the argument it goes:
- If one has donkey brains, then they make foolish decisions.
- Frank does not have a donkey brain.
- Therefore, he does not make foolish decisions.