PHIL 2110 Lecture Notes - Lecture 11: Modus Ponens, Destructive Dilemma, Constructive Dilemma

• School: University of Guelph
• Department: Philosophy
• Course: PHIL 2110
• Professor: Yussif Yakubu

Document Summary

D v o, d i, o i i. This is a common form of dilemma, where both disjuncts lead to the same simple conclusion. It has the form: p v q, p r and q r r. Dilemma (dl): which have the same consequent, infer their consequent: from a disjunction and two conditionals whose antecedents are the disjuncts, and, in symbols: from p v q, p r and q r, stated separately, infer r, e. g. A v f, a b, f i, i b i: a v f, a b, f i, i b. 3,4 mt: i, d, o, d & o 5,6 conj, (d v o, i (d v o, (d v o, i, i. 11 dn: a, b, b, i, a i, i. But don"t worry about memorizing them; just remember dl: let"s prove validity of latter: a b, c d, b v d a v c, example.