In the realm of logic and argumentation, identifying a fallacy in an opponent's reasoning is often seen as a powerful way to dismantle their argument. However, there's a specific formal fallacy known as the "argument from fallacy," also called the "fallacy fallacy," the "fallacist's fallacy," or the "bad reasons fallacy." This error occurs when someone analyzes an argument, correctly identifies a fallacy within it, and then incorrectly infers that,
because the argument contains a fallacy, its conclusion must therefore be false. This line of reasoning is itself flawed, as the presence of a fallacy only means the argument fails to prove its conclusion, not that the conclusion itself is untrue.
The general form of an argument from fallacy can be expressed as: "If P, then Q. P is a fallacious argument. Therefore, Q is false." This structure reveals its nature as a special case of denying the antecedent. In this scenario, the antecedent is an entire argument that is fallacious, rather than a simple false proposition. Just as a false antecedent can still lead to a true consequent, a fallacious argument can still have a conclusion that happens to be true. The error lies in assuming that the conclusion of a fallacious argument *must* be false simply because the reasoning used to support it was faulty. The fact that an argument is fallacious only indicates that it cannot successfully prove its conclusion; it does not automatically invalidate the conclusion itself.
Distinguishing Flawed Reasoning from False Conclusions
It's crucial to understand that demonstrating a flaw in an argument's reasoning does not necessarily mean its conclusion is false. A conclusion might be true for other reasons, or it might be true by coincidence, even if the argument presented for it is fallacious. For example, consider Alice's argument: "All cats are animals. Ginger is an animal. Therefore, Ginger is a cat." This is a fallacious argument (specifically, affirming the consequent). If Bob responds, "You have just fallaciously affirmed the consequent. You are incorrect. Therefore, Ginger is not a cat," Bob has committed the argument from fallacy. Ginger might or might not be a cat, but the fact that Alice's argument was fallacious does not, by itself, prove that Ginger is not a cat.
Another illustration: Alice states, "I speak English. Therefore, I am English." This is a package-deal fallacy, assuming that speaking English and being English always go together. If Bob replies, "Americans and Canadians, among others, speak English too. By assuming that speaking English and being English always go together, you have just committed the package-deal fallacy. You are incorrect. Therefore, you are not English," Bob is again employing the argument from fallacy. Alice's conclusion (that she is English) might be false, but Bob's reasoning for its falsehood is fallacious because it relies solely on the identification of Alice's logical error.
The Danger of Impugning Credibility
The argument from fallacy can also manifest as a form of *ad hominem* appeal. By pointing out an opponent's logical error, one might attempt to impugn their credibility or good faith, thereby swaying the audience without directly addressing the substance of the opponent's argument. This tactic undermines the speaker rather than engaging with their actual claims. William Lycan identifies a related aspect of the fallacy fallacy as "imputing fallaciousness to a view with which one disagrees but without doing anything to show that the view rests on any error of reasoning." This goes beyond simply concluding a statement is false because its argument is fallacious; it involves treating an argument's fallaciousness as self-evident without first demonstrating that any fallacy is present at all. In certain contexts, this can even become a form of begging the question or a special case of *ad lapidem*, where a claim is dismissed as absurd without providing evidence.
It's also important to note that one cannot use the argument from fallacy against a position to prove one's own position. If Charlie argues, "Bob's argument that Ginger is not a cat is fallacious. Therefore, Ginger absolutely must be a cat," Charlie is also committing the argument from fallacy. The identification of a fallacy in one argument does not automatically validate the opposing conclusion. The presence of a fallacy simply means the argument in question is not a reliable path to its conclusion, leaving the truth value of the conclusion open to further, sound argumentation.
