Fallacies Involving Credibility:
Appeal to Authority
(Argumentum ad Verecundiam)

An authority is someone whose word carries special weight because of expertise in some area of knowledge, such as law, science, or medicine.

It is perfectly appropriate to rely on the testimony of authorities if the conditions of credibility are satisfied. If they are not satisfied, however, the appeal to authority is fallacious.

The first condition for credibility is that the alleged authority be competent-- an expert on the subject matter in question.

The second condition is that the alleged authority be objective.


When Should We Rely On Authorities?

The use of authorities is appropriate only when the issue in question requires specialized knowledge or skill that the ordinary person does not possess. If the issue is not a technical one, if it is a matter of common sense, or if it is a value judgment, a political view, or an observation about human nature, then the ordinary person is capable of understanding the evidence for it and should not be asked to rely on someone else's judgment.


The Fallacy of Ad Hominem

Fallacies Involving Credibility

© Copyright 1998, W.W. Norton & Co.