---
title: "Logical Fallacy"
description: "An error in reasoning that weakens an argument. Formal fallacies break the logical structure; informal fallacies fail because of their content or context."
last_updated: "2026-08-02"
---

# Logical Fallacy

An error in reasoning that weakens an argument. Formal fallacies break the logical structure; informal fallacies fail because of their content or context.

*Example: "My grandfather smoked and lived to 95, so smoking isn't harmful" — the facts may be true, but the conclusion doesn't follow.*

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