Ad hominem
An
ad hominem argument, also known as
argumentum ad hominem (
Latin, literally "argument against the person") or
attacking the messenger [or
shooting the messenger], involves replying to an argument or assertion by attacking the person presenting the argument or assertion rather than the argument itself. It is a
logical fallacy.
A (fallacious) ad hominem argument has the basic form:
#
A makes claim
X.#There is something objectionable about
A.#Therefore claim
X is false.The first statement is called a 'factual claim' and is the pivot point of much debate.The last statement is referred to as an 'inferential claim' and represents the reasoning process. There are two types of inferential claim, explicit and implicit.
Ad hominem is one of the best-known of the logical fallacies usually enumerated in introductory
logic and
critical thinking textbooks. Both the fallacy itself, and accusations of having committed it, are often brandished in actual discourse (see also
Argument from fallacy). As a technique of
rhetoric, it is powerful and used often, despite its inherent incorrectness.
In contrast, an argument that instead relies (fallaciously) on the
positive aspects of the person arguing the case is known as
appeal to authority.
In Logic
An
ad hominem fallacy consists of asserting that someone's argument is wrong and/or he is wrong to argue at all
purely because of something discreditable/not-authoritative about the person or those persons cited by him rather than addressing the soundness of the argument itself. The implication is that the person's argument and/or ability to argue correctly lacks authority. Merely insulting another person in the middle of otherwise rational discourse does not necessarily constitute an ad hominem fallacy. It must be clear that the purpose of the characterization is to discredit the person offering the argument, and, specifically, to invite others to discount his arguments. In the past, the term
ad hominem was sometimes used more literally, to describe an argument that was based on an individual, or to describe any personal attack. However, this is not how the meaning of the term is typically introduced in modern logic and rhetoric textbooks, and logicians and rhetoricians are in agreement that this use is incorrect.
Examples::"You claim that this man is innocent, but you cannot be trusted since you are a criminal, as well."
"You feel that abortion should be illegal, but I disagree, because you are uneducated and poor."
"Only right-wing nutjobs believe that homosexuals account for one to two percent of the population."Not all
ad hominem fallacies are insulting:
Example: :"Paula says the umpire made the correct call, but this is false, because Paula is too important to pay attention to the game."
This is an
ad hominem fallacy, even though it is saying something positive about the person, because it is addressing the person and not the topic in dispute.
Linguistically
In common language, any personal attack, regardless of whether it is part of an argument, is often referred to as
ad hominem.
Three traditionally identified varieties are
ad hominem abusive or
ad personam,
ad hominem circumstantial, and
ad hominem tu quoque.
Ad hominem abusive or ad personam
Ad hominem abusive (also called
argumentum ad personam) usually and most notoriously involves insulting one's opponent, but can also involve pointing out factual but damning character flaws or actions. The reason that this is fallacious is that — usually, anyway — insults and even damaging facts simply do not undermine what logical support there might be for one's opponent's arguments or assertions;
argumentum ad personam short-circuits these potential arguments from logic in favor of a direct attack on the opponent's authority.
Example: :"You can't believe Jack when he says there is a
God because he doesn't even have a job."
Ad hominem circumstantial
Ad hominem circumstantial involves pointing out that someone is in circumstances such that he is disposed to take a particular position. Essentially,
ad hominem circumstantial constitutes an attack on the bias of a person. The reason that this is fallacious is that it simply does not make one's opponent's arguments, from a logical point of view, any less credible to point out that one's opponent is disposed to argue that way. Such arguments are not necessarily
irrational, but they are not correct according to strict logic. This illustrates one of the differences between rationality and logic.
Examples:
"Tobacco company representatives are wrong when they say smoking doesn't seriously affect your health,
because they're just defending their own multi-million-dollar financial interests."
"He's physically addicted to nicotine. Of course he defends smoking!"
Of course, such statements could also be reworded to avoid the logical fallacy:
"Tobacco company representatives may be
biased when they say smoking doesn't seriously affect your health,
because of their own multi-million-dollar financial interests. Thus, such statements may be wishful thinking, or even outright lies, on their part."
"He's physically addicted to nicotine. Therefore, his defense of smoking may be
biased."
In the following example Jennifer's comment is an
ad hominem circumstantial attack against Chris's statement:
Chris: "Women should be able to be topless everywhere men can be."
Jennifer: "You're just saying that because you want to see women's breasts."
The
Mandy Rice-Davies ploy, "Well, he would [say that], wouldn't he?" is a use of this fallacy.
Ad hominem tu quoque
Ad hominem tu quoque refers to an irrelevant accusation of hypocrisy. Accusations of hypocrisy are inadmissible in legal and scientific debate, and can be distractions from the business of politics. That is, it isn't relevant to the credibility of a didactic argument whether its presenter has trod over the principle he espouses. For example, a corrupt lawyer who prosecutes embezzlers may be a sleaze, but in a properly organized legal system there can be no arguments
against his defendant just because of that.
You-too version
This form of the argument is as follows:
A makes criticism
P.
A is also guilty of
P.:Therefore,
P is dismissed.
This is an instance of the
two wrongs make a right fallacy.
Example:
"He cannot accuse me of libel because he was just successfully sued for libel."
Inconsistency version
This form of the argument is as follows::A makes claim P.:A has
also made claims which are inconsistent with P.:Therefore, P is false (or is dismissed).
If the conclusion is that "P is false", then this is a
logical fallacy because the conclusion that P is false does not follow from the premises; even if A has made past claims which are inconsistent with P, it does not necessarily prove that P is either true or false. [After all, A might have changed his/her mind.]
Example:
"You say airplanes are able to fly because of the laws of physics, but this is false because twenty years ago you also said airplanes fly because of magic.""US Democrats say that we shouldn't participate in war in Iraq, but they supported it after 9/11.""US Republicans say that CIA intelligence is faulty, but they relied on it when we sent troops to Iraq."Guilt by Association
Guilt by Association is a type of ad hominem fallacy that attacks a person because of the similarity between the views of someone making an argument and other proponents of the argument.
This form of the argument is as follows::A makes claim P.:B's also make claim P.:Therefore, A is a B.
Examples:
"You say the gap between the rich and poor is unacceptable, but communists also say this, therefore you are a communist"This fallacy can also take another form::A makes claim P.:Bs make claim P and Q:Therefore, A makes claim Q.
Examples:
"You say the gap between the rich and poor is unnacceptable, but communists also say this, and they believe in revolution. Thus, you are a danger to the State."The
argumentum ad hominem is a
genetic fallacy and
red herring, and is often (but not necessarily) an
appeal to emotion. Argumentum ad hominem includes
poisoning the well.
*"
And you are lynching Negroes"
*
fundamental attribution error*
validity* Nizkor.org.
Fallacy: Ad Hominem.
* Nizkor.org.
Fallacy: Circumstantial Ad Hominem.
* Philosophy.lander.edu.
Argumentum Ad Hominem
