The relationship described as being opposites and as affirming and denying the same predicate of the same subject is known as what?

• A. Opposition
• B. Equivalence
• C. Implication
• D. Causation

Answer: (B)

This is about how two propositions relate as opposites in the traditional square of opposition. When two statements are opposites in the strong sense, they form a contradictory pair: one affirms the predicate of the subject while the other denies it. Because they assert opposite things about the same subject and predicate, they cannot both be true and cannot both be false. That immutable opposition is the hallmark of the contradictory relationship.

Equivalence, by contrast, means the two propositions always share the same truth value, which is not about denying or affirming the same predicate in opposition. So it doesn’t fit the described relation as well as opposition does.