PHI 1101 Lecture 14: March 1st, 2018

• School: University of Ottawa
• Department: Philosophy
• Course: PHI 1101
• Professor: Vincent Bergeron

Document Summary

Valid step: if the first step is true, then the step afterwards must be true as well. Valid inference: if all of the steps in the inference are true, the conclusion must be true. Given one premise, you can validly derive the conclusion. The first step should be the negation of the conclusion. I. e. if conclusion is ~a the first step would be a. If there is any contradiction in the steps then the reduction to absurdity has occurred and you get the required conclusion. Only do reduction to absurdity if it is specifically asked for in the question. Rules that are used on the exam will be given on the exam with the proofs. Fallacies will not be given so you must know them. First type symbolize the following statements using the dictionary provided. Second type symbolize the following arguments using the dictionary given and identify the form used and identifying if it is valid.