Kelley 2014 indicates that the four types of relationships are defined as

Kelley 2014 indicates that the four types of

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categorical propositions: contrary, subcontrary, contradiction and subalternate. Kelley (2014) indicates that the four types of relationships are defined as follows: Contraries means that a pair of propositions cannot both be true, however, they can both be false. Subcontraries is the opposite of contraries in which a pair of propositions cannot both be false, but they can both be true. Contradictory on the other hand has a pair of propositions with opposite truth values. It means that they cannot at the same time both be true or false. Subalternate means that if universal is true, then particular must also be true. However, it doesn't work vice versa. If
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THE SQUARE OF OPPOSITION3particular is true, then universal is false. To summarize the Square of Opposition, "Types A and Eare contraries, Types I and O are subcontraries, Type A and O are contradictories, Type E and I are contradictories, Type I is subalternate to A, Type O is subalternate to Type E" (McIntire, 2013, p 58). The Square of Opposition clarifies the statement's truth value by analyzing the logical relationships between the categorical propositions. By doing so, the method can be used to translates ordinary statements into the correct standard-form of a proposition.In standard-form of a proposition, a statement can present the members of the classes as all being universal or some being particular. The statement can also be presented as a positive claim (affirmation) or a negative claim (negation). Chapter 9 of the textbook, Critical Thinking, exhibits the four types of categorical propositions. Each categorical proposition is given a letter to represent the claim structure. In each structure, the first blank will be filled with a subject,
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