As per square of opposition, which of the following propositions are…
2023
As per square of opposition, which of the following propositions are contradictories?
A. All birds are apes.
B. No birds are apes.
C. Some birds are apes.
D. Some birds are not apes.
Choose the correct answer from the options given below:
Answer: C. B and C only — ConceptIn the traditional square of opposition, categorical propositions are classified by quantity and quality: A is universal affirmative, E is universal…
- A.
C and D only
- B.
A and C only
- C.
B and C only
- D.
B and D only
Show answer & explanation
Correct answer: C
Concept
In the traditional square of opposition, categorical propositions are classified by quantity and quality: A is universal affirmative, E is universal negative, I is particular affirmative, and O is particular negative.
Contradictory propositions differ in both quantity and quality. They cannot both be true and cannot both be false; the contradictory pairs are A–O and E–I.
Application
Classify the four propositions in the stem by their standard forms:
Proposition | Standard form |
|---|---|
A — All birds are apes | A — universal affirmative |
B — No birds are apes | E — universal negative |
C — Some birds are apes | I — particular affirmative |
D — Some birds are not apes | O — particular negative |
Contrast
C and D correspond to I and O; both are particular propositions and differ only in quality.
A and C correspond to A and I; both are affirmative propositions and differ only in quantity.
B and C correspond to E and I; they differ in both quantity and quality.
B and D correspond to E and O; both are negative propositions and differ only in quantity.
Result
Therefore, the contradictory pair among the offered choices is B and C only.