Law of the Fallacy Validity

The principle that under specific conditions, what appears to be a fallacy can actually be valid reasoning. The law acknowledges that context matters: an argument that commits a fallacy in one setting may be perfectly reasonable in another. Ad hominem, attacking the person, is fallacious in formal debate but valid when assessing credibility (you wouldn't trust a tobacco company's research on smoking). Appeal to authority is fallacious when the authority is irrelevant but valid when expertise is genuine. Slippery slope is fallacious when speculative but valid when causal chains are real. The law of the fallacy validity reminds us that fallacy labels are not absolute; they're tools, not weapons. What matters is not whether an argument fits a fallacy pattern but whether it's reasonable in context.

Example: "He accused her of ad hominem for mentioning the speaker's industry funding. She invoked the law of the fallacy validity: attacking the person is valid when their credibility is relevant. The funding mattered; the ad hominem was justified. He called it a fallacy; she called it context. She was right."

by Dumu The Void February 17, 2026

Law of the Valid Fallacies

The principle that there exists a class of arguments that are technically fallacious by formal standards yet genuinely valid in practice—reasoning that works even though it breaks the rules. These "valid fallacies" include arguments that persuade reasonable people despite logical flaws, inferences that lead to true conclusions through invalid steps, and reasoning that succeeds where formal logic fails. The law of the valid fallacies acknowledges that human reasoning is richer than formal logic, and that sometimes the technically invalid is practically sound. It's the logic of "it shouldn't work, but it does," of the intuitive leaps that turn out right, of the arguments that convince because they're right even though they're wrong by the book.

Example: "Her argument was technically fallacious—circular reasoning, begging the question. But it was also true, and everyone knew it. The law of the valid fallacies said: sometimes the fallacy is valid. The circularity didn't make it false; it just made it formally invalid. Formal invalidity and practical truth can coexist."

by Dumu The Void February 17, 2026