Difference between revisions of "Valid argument"
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| − | + | An argument is '''valid''' when it contains no logical fallacies. Such arguments are not necessarily [[sound argument|sound]], because the premises may be false. For instance, the following syllogism is valid but has a false conclusion: | |
| − | + | * All animals are dogs. (False premise/All A are B.) | |
| − | + | * All dogs are terriers. (False premise/All B are C.) | |
| − | All animals are dogs. (False premise/All A are B.) | + | * Thereforse, all animals are terriers. (False conclusion: not all animals are terriers. Valid logic: If all A are B, and all B are C, then all A are C.) |
| − | All dogs are terriers. (False premise/All B are C.) | ||
| − | Thereforse, all animals are terriers. (False conclusion: not all animals are terriers. Valid logic: If all A are B, and all B are C, then all A are C.) | ||
==Blog posts== | ==Blog posts== | ||
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==See also== | ==See also== | ||
| − | *[[Sound | + | *[[Sound argument]] |
[[Category:Concepts]] | [[Category:Concepts]] | ||
| − | {{ | + | {{stub}} |
Revision as of 07:06, 23 January 2011
An argument is valid when it contains no logical fallacies. Such arguments are not necessarily sound, because the premises may be false. For instance, the following syllogism is valid but has a false conclusion:
- All animals are dogs. (False premise/All A are B.)
- All dogs are terriers. (False premise/All B are C.)
- Thereforse, all animals are terriers. (False conclusion: not all animals are terriers. Valid logic: If all A are B, and all B are C, then all A are C.)
Blog posts
- [1] (tangentially related)
