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