The red herring logical fallacy, probably named after an English philosopher who used kipper (a strong-smelling smoked fish) to throw hounds off the scent of the rabbit, is an argument style in which an irrelevant topic is presented in an attempt to divert the argument from the original issue. The arguer then makes the claim of  “winning” the argument by directing the argument from the initial topic to another, often unrelated topic. This fallacy is somewhat related to the non sequitur.

The red herring “reasoning” uses the following steps:

• Topic A is under discussion.
• Topic B is introduced under the guise of being relevant to topic A, even though topic B has no relevance to topic A.
• Topic A ends up being abandoned.

This sort of “reasoning” is fallacious because changing the topic of discussion does not count as an argument against a claim — once again, the only point that should matter in an argument is the quality and the quantity of evidence.

Example of a red herring

Anti-vaccine activists use this quite a bit in their arguments about the safety and effectiveness of vaccines. A red herring argument often used would take this form:

• Anti-vaxxer — vaccines cause autism.
• Pro-vaxxer — there is no evidence in hundreds of studies that vaccines are linked to autism.
• Anti-vaxxer — there’s aluminum in vaccines. Aluminum causes autism.
• Pro-vaxxer — there is no evidence that aluminum is linked to autism.
• Anti-vaxxer — but there are adjuvants in vaccines.
• Pro-vaxxer — sigh.