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
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