VENN DIAGRAMS AND THE MODERN SQUARE OF OPPOSITION
Aristotelian Standpoint:
Universal propositions about existing things have existential import – they imply
the existence of the things talked about
Boolean Standpoint:
Universal propositions about existing things lack existential import – they do not
imply the existence of the things talked about
NOTE: in this class, we will be adopting the Boolean standpoint
Modern Square of Opposition:
Logically Undetermined
A ------------------------------------------ E
| \
/ |
Logically
|
\
/
| Logically
Undetermined |
Contradictory
| Undetermined
|
|
|
/
\
|
| /
\ |
I ------------------------------------------- O
Logically Undetermined
Contradictory Relation:
Two propositions stand in the Contradictory relation just in case they necessarily
have opposite truth values.
Logically Undetermination Relation:
Two propositions stand in the Logically Undetermined relation nothing can be
determined regarding the truth value of one from the truth value of the other