This fallacy occurs when an argument uses the authority of a non-expert figure as a reason to support the conclusion. It is very common to appeal to a person’s admiration of a particular person, especially famous actors, as a way to persuade her to believe an argument. Simply because Tom Cruise only drinks Pespi, does not mean that Pepsi is the best soda since Tom Cruise is not an expert of cola products. Be careful of arguments that appeal to an authority figure who is not necessarily an authority on the subject being discussed.
Example Argument: “President Obama hates football, so it must be bad.”
Premise: President Obama hates football
Conclusion: Football must be bad
While President Obama may be an authority on many things, including U.S. policy, this does not make him an expert on football. Just because Obama hates football does not mean that it is true that others must hate football too. Obama is not a qualified authority figure on football.