Validity vs Truth; Argument vs Proposition YouTube Lecture Handouts

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Validity vs Truth; Argument vs Proposition | Philosophy | Logic | NTA NET

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.

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