affirmation of the consequent

logic

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July 23, 2026

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Affirmation of the consequent is a logical fallacy where one incorrectly infers the truth of the antecedent of an implication from the truth of the consequent. This means that if a statement is in the form "If A, then B," and B is true, it does not automatically mean A is also true.12

For example, consider the statement: "If it rains, then the game is cancelled." If the game is indeed cancelled, it is a fallacy to conclude that it must have rained. The game could have been cancelled for other reasons. This type of reasoning is also known as the fallacy of the consequent.13

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applied logic
Formal fallacies
…B; not-A; therefore, not-B”) and affirming the consequent (“If A, then B; B; therefore, A”). The invalid nature of these fallacies is illustrated in the following examples:
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…B; not-A; therefore, not-B”) and affirming the consequent (“If A, then B; B; therefore, A”). The invalid nature of these fallacies is illustrated in the following examples:
Read More