subcontrary
/sʌbˈkɒntrəri
/Logic, dated
adjective
Denoting propositions which can both be true, but cannot both be false (e.g. some X are Y and some X are not Y).Similarly, ‘some unicorns have horns’ and ‘some unicorns do not have horns’ are both regarded as false, and so they are not subcontrary.’...
- Paradox seems to arise when conditional statements have subcontrary statements as antecedent and consequent.
- It follows that high or low probability are contrary to necessity of opposite polarity, and subcontrary to possibility of opposite polarity.
noun (plural subcontraries)
A subcontrary proposition.Again, I and O propositions are subcontrary, but not contrary or contradictory....
- The case of subcontraries will be revealed to include an unjustified presupposition in the section concerning the modern square of opposition.
- Given that traditional logicians did think the subcontraries have ‘existential import’, how do we resolve the apparent contradiction?
Origin
Late 16th century: from late Latin subcontrarius, translation of Greek hupenantios.