Quantifier Rules Flashcards
Some
At least one, could be all.
ie; Some animals are bears (Animals -some- Bears)
Reversal of Some
Directly reversible. The reversal of some is also some.
ie; Animals -some- Bears
Reversal: Bears -some- Animals
Most
More than half, at least 50.1%
ie; Most SCOTUS Justices graduated from Harvard (SCOTUS Justice -most- Harvard Grad)
Reversal of Most
Not directly reversible. The reversal of most is some.
ie; SCOTUS Justice -most- Harvard Grad
Reversal: Harvard Grad -some- SCOTUS Justices
All
Every single one.
ie; All humans are animals (Human –> Animal)
Reversal of All
Not directly reversible. The reversal of all is some.
ie; Human –> Animal
Reversal: Animal -some- Human
Valid Deductions/Conclusions With Quantifiers
Rule #1
Premises MUST contain a sufficient and necessary condition.
ie; A –> B
Exception to Quantifier Deductions/Conclusion Rule #1
Premises contain at least TWO most statements with the LEFT side in common.
ie; A -most- B
A -most- C
Con: B -some- C
Valid Deductions/Conclusions With Quantifiers
Rule #2
Premises MUST have a sufficient condition in common. The sufficient of the conditional statement must match the RIGHT side of the quantifier statement.
ie; A -some- B
B ——–> C
Con: A -some- C
The arrow in the deduction chain must point AWAY from the some statement.
ie; A -some- B —> C
Con: A -some- C