34-160 Lecture Notes - Fall 2018 Lecture 3 - Modus tollens, Disjunctive syllogism, Logical reasoning

• School: University of Windsor
• Department: Philosophy
• Course: PHIL 1600
• Professor: David Guetter

Document Summary

Deductive argument: one in which it is claimed that. The conclusion follows necessarily from the premises. True premises make it impossible for the conclusion to be false. Inductive argument: one in which it is claimed only that. True premises make it improbable for the conclusion to be false. Key words/phrases: deductive: necessarily, certainly, definitely. Strength of argument: deductive: conclusion necessarily true. Types of arguments (=context: deductive: mathematics, geometry, definitions. Thus, sue has a part-time job: inductive. If the premises are true, then its probably true that sue has a part- time job. All second-year" students hahve between ten and 19 course credits. So sue has at least ten course credits: for sure, hence deductive. All second-year" students have between ten and 19 courts. So sue ashas ten course credits: maybe, hence inductive. Logical analysis tells us whether a deductive argument is valid or invalid: valid deductive argument: true premises make it impossible for the conclusion to be false.