Fallacy of exclusive premises
From Wikipedia, the free encyclopedia
The fallacy of exclusive premises is a formal fallacy committed in a categorical syllogism that is invalid because both of its premises are negative.
Example:
- No mammals are fish.
- Some fish are not whales.
- Therefore, some whales are not mammals.
It is a syllogistic fallacy because at least one premise of a given syllogism has to be affirmative.
| Argument from fallacy | Fallacy of modal logic | Masked man fallacy | Appeal to probability
|
|
|---|---|
| Fallacy of propositional logic: | |
| Affirming a disjunct | Affirming the consequent | Commutation of Conditionals Denying a conjunct | Denying the antecedent | Improper Transition |
|
| Fallacy of quantificational logic: | |
| Existential fallacy | Illicit Conversion | Quantifier shift | Unwarranted contrast | |
| Syllogistic fallacy: | |
| Affirmative conclusion from a negative premise | Negative conclusion from an affirmative premise Exclusive premisses | Necessity | Four-term Fallacy | Illicit major | Illicit minor | Undistributed middle |
|
| Other types of fallacy | |
This article was originally based on material from the Free On-line Dictionary of Computing, which is licensed under the GFDL.
