The affirming the consequent fallacy represents an invalid form of the conditional argument. The conditional argument begins with an "if-then" statement i.e.) "If LeBron James stays healthy, then the Cavs will win the championship." These statements have two parts: the antecedent or "if" clause and the consequent or "then" clause. A valid conditional argument takes one of two forms. The first form-affirming the antecedent or modus ponens-occurs when the truth of the antecedent is used to conclude the truth of the consequent. In this case, "If LeBron James stays healthy, then the Cavs will win the championship. LeBron stays healthy. QED: The Cavs win the championship." The second form-denying the consequent or modus tollens-occurs when the falsity of the consequent is used to conclude the falsity of the antecedent. "If LeBron James stays healthy, then the Cavs will win the championship. The Cavs do not win the championship. QED: LeBron did not stay healthy."
The affirming the consequent fallacy occurs when the truth of the consequent is used to prove the truth of the antecedent. In this case: "If LeBron James stays healthy, then the Cavs will win the championship. The Cavs win the championship. QED: LeBron stayed healthy." Although this series of statements appears to make sense (as affirming the consequent fallacies often do), the logic fails (San Jose University).
Argument from Analogy (or False Analogy)
Analogies-or comparisons between two similar objects-represent a valid form of argumentation. However, analogies must be well constructed in order to work effectively. Poor analogies can easily become fallacious. The argument from analogy (or false analogy) fallacy occurs when two objects that share one trait are supposed to have additional traits in common without any supplemental proof. The existence of one common trait does not prove the existence o
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