Valid Argument/Examples/Trout have Wings
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Example of Valid Argument
The following is a valid argument with false premises:
- All trout are mammals.
- All mammals have wings.
- Therefore all trout have wings.
Proof
This is a categorical syllogism of the first figure, of the form $AAA$.
From Valid Patterns of Categorical Syllogism, this is seen to be a valid argument.
The premises, however, are false.
It follows that the argument, while valid, is unsound.
$\blacksquare$
Sources
- 1973: Irving M. Copi: Symbolic Logic (4th ed.) ... (previous) ... (next): $1$ Introduction: Logic and Language: $1.3$: Truth and Validity