Fallacy of exclusive premises


 
Name of fallacy Fallacy of exclusive premises
Aliases  
Type Deductive Argument, Formal Argument
Description  
Example No mammals are fish.
Some fish are not whales.
Therefore, some whales are not mammals.

Form 
Treatment Dealt with by showing the error in the formal logic. For example:

No mammals are fish.
Some fish are not whales.
Therefore, some whales are not mammals.

By implication because some fish are not whales the remaining or part of the remaining fish are whales. If some fish are whales then according to the first premise these whales are not mammals. The error is in the implication. You are told some fish are not whales but you are not told anything about the remaining fish. They too might not be whales.

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