Which of the following statements are sub-contraries?

1.All sparrows are birds.

2.No sparrows are birds.

3.Some sparrows are birds.

4.Some sparrows are not birds.

A3 & 4 only ✓ Correct

B2 & 4 only

C1 & 2 only

D2 & 3 only

Correct answer: (A) 3 & 4 only

Explanation

Statements 3 and 4 are the subcontraries.

Statement 3, 'Some sparrows are birds', is a particular affirmative.

Statement 4, 'Some sparrows are not birds', is the particular negative on the same terms.

A particular affirmative and its particular negative are subcontraries, which can both be true but cannot both be false.

Statements 1 and 2 are universals, so they do not stand in the subcontrary relation.

Hence the subcontrary pair is the third and the fourth.

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