PHI 1101 Lecture Notes - Lecture 12: Syllogism, Venn Diagram

• School: University of Ottawa
• Department: Philosophy
• Course: PHI 1101
• Professor: Sardar Hosseini

Document Summary

Phi1101 chapter 5: more valid argument forms: categorical reasoning and venn diagrams. Common types of deductive arguments: argument based on mathematics, argument from definition, sentential (propositional) deductive arguments, categorical syllogism. In categorical reasoning the statements or claims of interest are categorical statements. Categorical statements make simple assertions about categories, or classes, of things. Categorical syllogism consist of three parts: major premise, minor premise, conclusion. Validity: use venn diagrams to evaluate the validity/invalidity of categorical syllogism, must evaluate each premise (major and minor) separately, then see if they support the conclusion. Categorical claim: contains two distinct categories: the subject and the predicate. Four standard forms (pure forms: all (universal affirmation ua, no (universal negation un, some (particular affirmation pa, some are not (particular negation pn) Valid categorical syllogism is such that its premises are true, then conclusion must be true.