The fallacy fallacy, or argumentum ad logicam, is the informal logical fallacy that if an argument contains a logical fallacy the proposition is wrong. It takes the following form:
- Argument A supports the proposition P
- Argument A contains a logical fallacy.
- Therefore, P is false
An argument of that form is perfectly valid when all possible arguments for a proposition are fallacious - indeed showing that all propositions are fallacies or somehow wrong is the way to disprove something, barring the proposition being unprovable, of course.
However, due to the likely large number of arguments and fallacious arguments (from someone attempting a Gish gallop, for instance) in support of a proposition P, it would be easier to prove not P than to go about countering the various fallacious arguments, although this can be difficult when one's opponent is just JAQing off and otherwise spewing bullshit, not even directly claiming that P is true.
This fallacy's use is staggeringly common during internet debates, where pseudo-intellectualism reigns supreme. A person will seek out and attack any logical fallacy you use and dismiss your argument out of hand, without ever addressing the proposition. Fairly often, you might spot someone not even bother explaining why the fallacy is appropriate in that context - because it's not.
The following argument, forming a large part of Richard Dawkins's book The God Delusion, displays the fallacy fallacy:
- The argument from design supports the proposition "God exists."
- The argument from design is fallacious.
- Therefore, God does not exist.
| Articles about logical fallacies|
|Affirming the consequent||Denying the antecedent|
|Fallacious argument styles|