People often make errors in deciding whether phrases with the format "If A is true, then B is true. A is not true. Therefore, B is not true" are valid or not. These errors are known as:

Question

Quizplus · Accepted Answer

These errors are known as denying the antecedent errors. This is because the argument assumes that the truth of the antecedent (the "if A is true" part) is necessary for the truth of the consequent (the "then B is true" part). However, this is not the case, and so the argument is invalid.

People Often Make Errors in Deciding Whether Phrases with the Format