fallacy

Appeal to authority

Also called: Argument from authority, Ad verecundiam

An appeal to authority treats a claim as true because an authority figure endorses it, especially when that person is not an expert on the subject or when experts in the field disagree.

How it works

Relying on expertise is often sensible; the fallacy lies in treating endorsement as proof, citing someone outside their field, or hiding a real expert disagreement. Fame and confidence borrow the credibility that only relevant evidence can supply.

Examples

"A famous actor says this supplement cures anxiety, so it must work."

Acting skill gives no special knowledge of pharmacology.

"A Nobel laureate in physics thinks this diet is best for weight loss."

Expertise in physics does not transfer to nutrition science.

How to spot it

Who is the authority, and is the question within their field?
Is the authority representative of expert opinion or an outlier?
Is any evidence given beyond the endorsement?

How to respond

Ask what evidence the authority relies on.
Check whether the relevant experts broadly agree.
Distinguish expert consensus, which is strong evidence, from a single quotation.