‘All republics are grateful’ and ‘Some republics are not grateful’ cannot both be true, and they cannot both be false. This is called as
contradictories
'All republics are grateful' is a universal affirmative (A-type) proposition, while 'Some republics are not grateful' is a particular negative (O-type) proposition with the same subject and predicate. On the classical square of opposition an A proposition and the O proposition of the same terms stand diagonally opposite each other.
Two propositions are contradictories when they can neither both be true nor both be false — exactly one must be true and the other false. The statement tells us these two 'cannot both be true, and they cannot both be false', which is precisely the definition of contradictories.
Contraries can both be false (though not both true), so they fail the second condition. The subaltern relation links a universal to its corresponding particular where the truth of the universal passes down to the particular; they can share truth-value, so this does not fit. 'Super altern' merely names the universal member of a subalternation pair and is not a relation of mutual exclusion at all. Only contradictories satisfy both stated conditions.
Correct answer: contradictories
Similar Questions
Which of the following is contrary to the statement "No mammals are birds"?
If the statement "Some animals are birds" is given as false then which of the following statements can be immediately inferred to be false?
Which of the following propositions can be directly inferred from the statement - "All mammals are four-legged animals?
Which of the following statements are contradictory to each other?
A. All objects are perishable.
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Among the following propositions two are related in such a way that they cannot both be true but can both be false. Select the code that states those two propositions.
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(a) Every student is attentive.
(b) Some students are attentive.
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If proposition 'some milk is curd' is taken to be true, then which of the following propositions can be false?
When subject and predicate of both the premises is same but they differ only in quantity, it is known as:
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Select the correct answer from the options given below:Among the following statements, two are contradictory to each other. Select the code that represents them.
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Important Questions from Classical Square of Opposition
Which of the following statements are so related that they can not both be true but could both be false?
A. All Biologists are outstanding teachers.
B. Some Biologists are outstanding teachers.
C. No Biologists are outstanding teachers.
D. Some Biologists are not outstanding teachers.
Choose the correct answer from the options given below:
Which of the following is contrary to the statement "No mammals are birds"?
If the statement "Some animals are birds" is given as false then which of the following statements can be immediately inferred to be false?
Which of the following propositions can be directly inferred from the statement - "All mammals are four-legged animals?
Which of the following statements are contradictory to each other?
A. All objects are perishable.
B. Some objects are not perishable.
C. Some objects are perishable.
D. No objects are perishable.
Choose the most appropriate answer from the options given below:
