PHL 101 Lecture Notes - Lecture 7: Obversion, Contraposition, Categorical Proposition
Document Summary
Conclusion from just one statement (follows immediately after the premise) Argument or syllogism - mediated inferences when you derive a conclusion from two or more premises. Conversion: no b are a - no a are b. No a are b, all a are non-b. All a are b, no a are non-b. Slightly more complicated way to think about double negation. Conversion - e or i and you can switch subject and predicate and produce logical statement. If two statements are logically equivalent that just means that one statement implies another statement. If one is true, any statement that is logically equivalent is also true. Contradictory opposition: truth of one statement implies falsehood of another statement. Square of opposition- visual representation of the relationships of each kind of proposition. If it is true, then it must be false that some sneakers are not shoes. If its true, then it must be false that some monkeys can y.
