Logical fallacy

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Note that an argument can be fallacious but still correct.  For instance:
 
Note that an argument can be fallacious but still correct.  For instance:
  
# All cats are mammals.
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# All fish live in the water.
# All cats are dogs.
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# All trout live in the water.
# Therefore all dogs are mammals.
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# Therefore all trout are fish.
  
The conclusion is accurate even though the premises and deductive method are incorrect.
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The premises are accurate and the conclusion is accurate, but it the conclusion is not a valid inference from the premises.  To see why, notice that we could use identical reasoning to prove that "all whales are fish."
  
 
Likewise, an argument can be logically sound but still wrong.
 
Likewise, an argument can be logically sound but still wrong.
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# Therefore, all spiders are insects.
 
# Therefore, all spiders are insects.
  
Some of the premises are factually incorrect.  However, the conclusion based is an accurate deduction based on those premises.
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Some of the premises are factually incorrect, and the conclusion is also untrue.  However, the conclusion is an accurate deduction based on those premises.
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==Examples of Fallacies==
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Here are a few examples for future articles:
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* [[Straw Man]]
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* [[Appeal to Emotion]]
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* [[Post Hoc Ergo Propter Hoc]]
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There are many more in the logical fallacies category.
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[[Category: Logical fallacies]]

Revision as of 08:53, 20 June 2006

A logical fallacy can be any one of a number of formal or informal mistakes in a deductive proof.

Note that an argument can be fallacious but still correct. For instance:

  1. All fish live in the water.
  2. All trout live in the water.
  3. Therefore all trout are fish.

The premises are accurate and the conclusion is accurate, but it the conclusion is not a valid inference from the premises. To see why, notice that we could use identical reasoning to prove that "all whales are fish."

Likewise, an argument can be logically sound but still wrong.

  1. All bugs are insects.
  2. All spiders are bugs.
  3. Therefore, all spiders are insects.

Some of the premises are factually incorrect, and the conclusion is also untrue. However, the conclusion is an accurate deduction based on those premises.

Examples of Fallacies

Here are a few examples for future articles:

There are many more in the logical fallacies category.

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