PHIL 111 Lecture Notes - Lecture 2: Formal Fallacy, Post Hoc Ergo Propter Hoc, If And Only If

• School: Queen's University
• Department: Philosophy
• Course: PHIL 111
• Professor: Jon Miller

Document Summary

Not all distinctions matter: a distinction without a difference . However, sometimes distinctions are vital: eg. Distinction between process of dying, moment of death, being dead. Most things are conditional; they depend in some way on something else: not all of their conditions are equivalent: some are necessary while others are sufficient. X is necessary for y iff the falsity/non-existence/non-occurrence of x ensures the falsity/non-existence/non-occurrence of y: eg. Air is a necessary condition for human life. But air is not a sufficient condition for human life; this shows that not all necessary conditions are also sufficient conditions. X is sufficient for y iff the truth/existence/occurrence of x ensures the truth/existence/occurrence of y: eg. A sufficient condition for quenching thirst is drinking cold beer. But drinking a cold beer is not a necessary condition for quenching thirst; this shows that not all sufficient conditions are necessary. We distinguish between general kinds of things vs. specific instances of those kinds.