At a recent ASR pub night one of our speakers was told that he had used an ad hominem to describe some of the targets of his talk, and I immediately noticed that the accuser was incorrect. Our speaker was an erudite man, so rather than butt in I allowed him to handle the complaint. He explained his opinions quite well – but not why what he’d said was not an ad hominem. So let’s attempt to clear the air, because the reasoning is easily understood.

The Latin phrase ad hominem literally means “to the person,” which means that when a claim has been made it is attacked not on its own merits, but on the perceived character of the person making it.

Recently people seem to have moved away from that definition and see any remark about a person as an ad hominem. Let’s examine three different scenarios that might explain this better. We will drag out the name of the notorious Fred Phelps, the self-proclaimed Pastor of the Westboro Baptist Church. He is probably best known for the website godhatesfags.com, and for picketing the funerals of anyone they perceive as being “soft” on homosexuality. Actually, this could create a fourth scenario; I’m certain that more than a few readers will immediately roll their eyes at the mention of his name and think, “Oh please no – not that idiot!” In a way it seems his name has become its own ad hominem, but as we shall see, that is not the correct use of the term either.

1. If I said “Fred Phelps is a jerk,” that is not an ad hominem; it is simply my opinion of the man. It may reflect poorly on me if I can’t justify it to some degree, but it doesn’t fit the criteria needed to be an ad hominem argument.
2. If I said “Fred Phelps is a jerk because of what he believes,” that also is not an ad hominem. It is my judgment of him as a person based on his beliefs, and could be entirely justified. If a person’s beliefs and actions are morally reprehensible, repugnant, or dangerous, then stating that they are not a nice person, by whatever language one chooses, is quite acceptable. At least to me it is.
3. If I said “Fred Phelps is wrong because he’s a jerk,” then that is an ad hominem. We may think that he is repugnant, and we may feel that persecuting someone for being gay is wrong (I hope we all do), but his beliefs should be examined on their own merits, not because of how we feel about him personally. The idea that someone can never have a good idea because they’re a jerk is the definition of an ad hominem argument taken to the extreme.

To further explain, let’s imagine that Mr. Phelps and I were taking a long road trip together (the very idea almost has me rushing for the shower), and I have worked out what seems to be an efficient route. But Mr. Phelps whips out the map and finds a better one, shorter, perhaps with better scenery, and better restaurants en route. Would I be justified in dismissing his idea because I think he’s a jerk? Obviously not. In fact, in that case I would be the fool. And no, I didn’t just ‘ad hom’ myself, as if that wasn’t abundantly clear by now.

By having a clear understanding of this quite simple concept we might avoid confusion in future. And by not falling back on misinterpretations so readily, we will be more able to judiciously examine the claims and arguments put forth through discourse and debate. Accusing someone of using an ad hominem has become all too easy these days; it can derail or truncate discussion, and it is quite often wrong.