PHI 1101 Lecture Notes - Lecture 2: Principle Of Bivalence

• School: University of Ottawa
• Department: Philosophy
• Course: PHI 1101
• Professor: Laura Byrne

Document Summary

The law of the excluded middle or the law of bivalence (meaning 2 values) Every proposition must either be true or false. Any middle proposition b/w truth and falsity is excluded. Jane is pregnant - she either is pregnant or not pregnant. Fuzzy logic (non classical) - contradicts this by saying there"s an infinite number of possibilities b/w t/f. Blurred logic (non classical) - contradicts w/ a meh or an ish (tri-valent) If a proposition is true, its negation must be false, if a proposition is false, its negation must be true. Propositions can be combined in groups or sets. Sets of propositions = inconsistent or consistent the way propositions are t/f. It is important to understand that consistency does not imply that all, or aany, of the sentences in a consistent set are, in fact, true.