Not To Be Confused With
Citing real experts is legitimate and often wise; it becomes a fallacy when the authority is outside their field, when experts disagree, or when “he said so” replaces evidence.
Authorities are valuable witnesses, not infallible proofs. A church father or scholar quoted on a point still has to be weighed; “a great name said it” is testimony to consider, not a conclusion to end the argument. In theology, even genuine authorities are read under Scripture and reason.