PHI 1101 Study Guide - Final Guide: Post Hoc Ergo Propter Hoc, Argument From Authority, Ad Hominem

• School: University of Ottawa
• Department: Philosophy
• Course: PHI 1101
• Professor: Dean Lauer

Document Summary

A fallacy is an error in reasoning. There are two types of fallacies: formal: an error in reasoning that can be de ned in terms of its form or bare logical structure alone, without reference to its content or what it is about. Informal: an error in reasoning that is not simply due to the pure form of the argument; thinking guided by our feelings rather than reason. If p then q: q is true, therefore, p must be true. If p then q: not p, therefore, certainly not q. Involves an attack on the person rather than the issue put forward by that person. Information about the author of some statement is used to discredit the statement, when the information is irrelevant to the truth or falsity of the statement. Strictly, the personal characteristics of individuals or their associates offering claims are irrelevant to the truth of those claims. Circumstantial ad hominem - attacking someone"s circumstance.