Is it an ad hominem attack to call somebody a troll?

Question

Case 1: Person A criticizes person B. Person B says "We shouldn't feed the trolls. Best not to engage."

Case 2: Person A voices their opinion on an issue being discussed on the forum. Person B says "Stop trying to bait and inflame. You frequently troll this site."

Are these ad hominem attacks? It seems to me that they are very straightforwardly ad hominem attacks - regardless of whether person A is a troll - as they call the person A's character into question instead of addressing what person A actually said.

Answer 1

While I agree in general with the other answers, I think they miss something very important. Ad hominem is a technical term, in a category, logical fallacy, that has a precise meaning: Something that is presented as (or appears as) a proof or disproof of an argument, but that does not legitimately address that argument.

In the examples you give, it is impossible to judge them as ad hominem without more context. Is Person A advancing an actual argument (whether weak or strong), that Person B wants people to discard solely on the basis of who Person A is? Or is Person A just making absurd personal accusations with no actual logical content (valid or not)?

Please note: It would be perfectly reasonable for someone to say "Person A has a long, consistent history of making worthless claims, therefore it is likely that this claim is worthless (and/or therefore it is likely to be not worth the time to listen and try to understand). It is, however, fallacious to say "Person A has a long consistent history of making worthless claims, therefore this current argument he is making is (or must be) invalid." No possible accidents of personal history are legitimate disproofs of any strong or valid argument.

Answer 2

Short Answer: Yes.

Long Answer:

Although ideally, all arguments should be evaluated on their merits, we often don't have the resources or know-how to do this. Therefore, we do rely on "fallacies" as a way saving ourselves some work. As such, people who appear to not be serious (or have a reputation for trolling) are subject to an ad hominem dismissal, respected authorities are often taken at face value, and so on.

Unfortunately, rigor isn't always practical, especially for the layperson. For instance, if I were asked to make a mathematical or physical argument, I'd start off taking some things for granted -- be they the consensus opinions of experts or even previously proven results (that I haven't validated myself). Likewise, I wouldn't likely engage anyone who I think is trolling or is part of the "lunatic fringe".

I'd know I'm committing a fallacy by doing so, yet this wouldn't deter me one bit.

Answer 3

It is indeed an ad hominem attack. However, if the person starting to argument does indeed meet the definition of a troll, then that ad hominem attack is indeed a proper response.

A troll doesn't make statements with the intent of having a rational and logical discussion, where we exchange logical arguments and therefore may look for logical fallacies like an ad hominem attack. A troll makes statements with the intent of starting nasty arguments, to make people feel bad, to make people so upset that they might make emotional statements they later regret. "He is a troll, ignore him" is excellent advice which robs the troll of his vile enjoyment of other people's misery, so it is the correct advice.

Obviously the same can be used as an ad hominem attack against a genuine argument that the respondent just didn't like and would prefer not to be heard by others. And it is of course possible that a troll did indeed have a correct but unpopular argument, which he makes not to get at the truth, but to be a troll. So there may be cases where you shouldn't enter a discussion with the troll, but still look at the argument he or she made.

Answer 4

There seem to be two very important things here: An insult isn't necessarily ad hominem (Argumentum ad hominem). Something can be a personal attack while not being a logical fallacy.

It becomes a logical fallacy if it is being used to counter or devalue and argument though, since then you're trying to use it as an argument. This is very important, someone may just insult you, not wanting to counter your argument with it.

Case 1

If B is trying to dismiss an argument A made in the criticism by saying B is a troll, that is an ad hominem fallacy.

Case 2

It is ad hominem if Person B is trying to dismiss an argument Person A made by calling A a troll.

If they just state that they think A is a troll, while not trying to mean that as a counter-argument, then no, that would not be a fallacy.

If stating that A's opinion is not to be taken since he is a known troll, that is ad hominem, as it doesn't actually engage the argument A made, but rather attacks A as a person to devalue their argument.

Based on an interesting read I just had on that: http://laurencetennant.com/bonds/adhominem.html