9.7: Glossary

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Bradley H. Dowden
California State University Sacramento

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contradiction in terms Applying two or more terms to give a logically inconsistent description. Calling a farmer's field a round square would be to use a contradiction in terms. Contradictions in terms are also called oxymorons.

contrary A pair of statements are contrary if they are inconsistent but both might be false. “It is less than 10” and “It is greater than 77” are contrary statements.

counterexample to a statement A true statement that is inconsistent with a previous statement and that is about some specific item in a category mentioned in the previous statement. "Spud Webb is a short basketball player" is a counterexample to "All basketball players are tall." We also can say Spud Webb is a counterexample.

generalization A generalization about a group is a statement about the group that says some, all, or a percentage of them have some property.

hypothesis An hypothesis is a claim that is proposed. If someone were to offer a possible explanation of some phenomenon, then that explanation would be an hypothesis.

logically inconsistent statements A group of statements that could not all be true together, in virtue of their meaning. Normally we drop the word “logically” during discussions of inconsistency.

oxymoron A contradiction in terms. Inconsistent phrases such as the living dead and exceptionally ordinary are oxymorons.

presuppositions A statement’s presuppositions are unsaid, relevant statements that would normally be taken for granted in making the statement. Saying, “I like your car” presupposes you do have a car. It doesn’t presuppose that 1 + 1 is 2.

refutation A successful disproof. Refuting a statement requires more than merely contradicting it.

self-contradiction Logical inconsistency within a single statement. Example: "Ahmed is taller than Steve, and Steve is taller than Ahmed."