This page is part of the EvoWiki encyclopedia of fallacies.
- Fallacy of exclusive premises
- Two negative premises
You commit this fallacy if you use only negative syllogisms (i.e. exclusive premises) to draw a conclusion.
- No A are B
- No C are A
- Thus, No C are B.
- Plants are not animals.
- Humans are not plants.
- Therefore, humans are not animals.
This argument is fallacious because both premises are exclusive. If the first premise is a negative syllogism, the other must be a positive: If it was shown that humans are plants, only then would the conclusion be logical.