week six

    Cards (12)

    • Quantified logic
      • subject - what statement is about
      • predicate - thing said about subject
      • quantifier expressions
    • Multiple place predicates (multiple subjects)
      • one place: "... is blue"
      • two place: "...is taller than..."
      • three place: "...likes...more than..."
      • four place: "...bought...from....for...."
      • etc.
    • Quantifier expressions
      • indicates how many things/how much stuff
      • numerically definite: 2/100/four
      • numerically indefinite: some/all
    • Generalisation
      • An ambiguous generalisation contains one or more quantifier expressions
      • Can be universal or existential
    • Universal generalisation
      "All" / "every"
    • Existential generalisation
      "Some" / "there are"
    • Conversion (reasoning with generalisation)
      • switching roles of subject and predicate
      • 'All cats are felines' - 'All felines are cats'
      • 'Every car is not a bike' - 'Every bike is not a car'
    • Complementation of terms
      I. Adding 'non' to front of term
      II. Taking away 'non'
      Swans = non-swans
    • Contrapositive
      I. convert generalisation; and
      II. complement all terms
      • conversion - 'all mammals are cats'
      • complement - 'all non-mammals are non-cats'
    • Obversion
      I. Turn generalisation from an affirmative to a negative, or vice versa
      II. Complement the predicate term
      1. 'some cats are fluffy'
      2. 'some cats are not fluffy'
      3. 'some cats are not non-fluffy'
    • Obversion form
      All Fs are Gs - All Fs are not non-Gs
    • Syllogisms
      I. 2 generalisations as the premises
      II. a generalisation as the conclusion
      III. 3 distinct class terms - 1/3 appear in both premises = 'middle term'