MODR 1711 Lecture Notes - Lecture 14: Obversion, Victorian Railways E Type Carriage
4 Oct 2017
School
Department
Course
Professor
Document Summary
Categorical propositions: 4 parts (subject, predicate, copula, quanti er) How can we make immediate one-step deductions? (obversion, conversion, contraposition) Obversion: negate the p term (non-p) and change the quality of the proposition (copula. Contraposition (switch s and p, negate s and p)) A type: all s is p - universal positive. E type: no s is p [all s is not p] - universal negative. I type: some s is p - particular positive. O type: some s is not p - particular negative. What happens when we take a convert/obvert/contrapose one of these categorical propositions: immediate deductions, conversion: All human beings are rational - all rational things are human beings. No dogs are cats - no cats are dogs. Some dogs are white - some white things are dogs. Some humans are not canadians - some canadians are not humans. All s is p - all s is not non-p.
