Which fallacy involves using an authority figure to support an argument without relevance to the subject?

The fallacy that involves relying on the opinion of an authority figure to support an argument, regardless of the authority's relevance to the subject at hand, is called Argumentum ad verecundium, commonly known as the appeal to authority. This fallacy occurs when someone asserts that a claim must be true simply because an authority figure believes it or supports it, rather than providing evidence or reasoning related to the argument itself.

This type of reasoning can be problematic because an authority figure's expertise in one field does not necessarily translate to credibility in another. For example, the opinion of a celebrity about a scientific issue may carry weight with some, yet that doesn't validate the accuracy of their claims. It's essential to evaluate arguments based on relevant evidence and logic rather than solely on the stature of the person making the claim.

The other fallacies listed do not pertain directly to the misuse of authority in this way. A Strawman fallacy misrepresents an argument to make it easier to attack, Argumentum ad logicam refers to arguing that a conclusion is false because the logic leading to it is flawed, and Argumentum ad antiquitatem appeals to tradition or what has been accepted in the past rather than to current evidence or reasoning.