# Validity vs Truth; Argument vs Proposition YouTube Lecture Handouts

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# Title: Validity vs Truth (Argument vs Proposition)

## Truth

- Individual proposition
- Single statement can be true or false
- Attribute of a proposition or statement
- Lake Michigan is the largest of Great Lakes

## Validity

- Does not apply to Single statement Attribute of an arguments
- If conclusion follows from premise, we say its valid
- All mammals have lungs (True proposition)
- All whales are mammals (True Proposition)
- Therefore, all whales have lungs (Valid Argument)
- Truth & Falsity of Argument does not determine validity and invalidity of argument
- Argument is valid does not guarantee the truth of its conclusion
- If conclusion follows from premise, we say its valid
- All mammals have lungs (True proposition)
- All whales are mammals (True Proposition)
- Therefore, all whales have lungs (Valid Argument)
- All 4-legged creatures have wings (False)
- All spiders have 4 legs (False)
- Therefore, all spiders have wings (False Conclusion – hence valid)
- All mammals have wings (false)
- All whales have wings (false)
- Therefore, all whales are mammals (true but invalid argument)
- If argument is valid and premise is true, we may be certain that conclusion is true
- If argument is valid and conclusion is false, not all the premises can be true.

✍ Manishika