A Brief Look at Logic PDF
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Summary
This document provides an overview of common argument patterns, including valid and invalid forms such as affirming the antecedent, denying the consequent, hypothetical syllogism, and disjunctive syllogism. It explores examples like the "raven barking" scenario and "Ajax stealing money" situations to illustrate these argument forms.
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A Brief Look at Logic Valid Argument Forms AFFIRMING THE ANTECEDENT (Modus Ponens) If p, then q. p. Therefore, q. If Raven barks, a burglar is in the house. Raven is barking. Therefore, a burglar is in the house. ...
A Brief Look at Logic Valid Argument Forms AFFIRMING THE ANTECEDENT (Modus Ponens) If p, then q. p. Therefore, q. If Raven barks, a burglar is in the house. Raven is barking. Therefore, a burglar is in the house. (Valid argument forms) DENYING THE CONSEQUENT (Modus Tollens) If p, then q. Not q. Therefore, not p. If it’s raining, the park is closed. The park is not closed. Therefore, it’s not raining. (Valid argument forms) Hypothetical Syllogism If p, then q. If q, then r. Therefore, if p, then r. If Ajax steals the money, he will go to jail. If Ajax goes to jail, his family will suffer. Therefore, if Ajax steals the money, his family will suffer. (Valid argument forms) Disjunctive Syllogism Either p or q. Not p. Therefore, q. Either Zein walked the dog, or he stayed home. He didn’t walk the dog. Therefore, he stayed home. Invalid Argument Forms AFFIRMING THE CONSEQUENT If p, then q. q. Therefore, p. All Gods are immortal If the cat is on the mat, she is asleep. She is asleep. Nabih Berri is immortal Therefore, she is on the mat. Nabih Berri is a God Invalid Argument Forms DENYING THE ANTECEDENT If p, then q. Not p. Therefore, not q. If the cat is on the mat, she is asleep. She is not on the mat. Therefore, she is not asleep.
