Ad hominem

"Personal attacks" redirects here. For the Wikipedia policy, see Wikipedia:No personal attacks.

An ad hominem (Latin for "to the man"), short for argumentum ad hominem, is an argument made personally against an opponent, instead of against the opponent's argument. Ad hominem reasoning is normally described as an informal fallacy, more precisely an irrelevance.

Types

See also; List of fallacies

Abusive

Abusive ad hominem (also called personal abuse or personal attacks) usually involves insulting or belittling one's opponents in order to attack their claims or invalidate their arguments, but can also involve pointing out true character flaws or actions that are irrelevant to the opponent's argument. This is logically fallacious because it relates to the opponent's personal character, which has nothing to do with the logical merit of the opponent's argument, whereas mere verbal abuse in the absence of an argument is not ad hominem nor any kind of logical fallacy.

Examples:

• "Candidate George's proposal about zoning is ridiculous. He was caught cheating on his taxes in 2003."
• "What would Margaret know about fixing cars? She is a woman."
• "What makes you so smart and all-knowing that you can deny God's existence? You haven't even finished school."
• "If Dr. Schweitzer is such a skilled heart surgeon, then why was he arrested for skinny-dipping in the ball pit at Chuck E. Cheese's?!"
• "Your fashion opinion isn't valid; you can't even afford new shoes."
• "Your exposition is highly correct and valid, but you don't have enough academic certification." (an example of the Credential fallacy)

An abusive ad hominem can apply to a judgment of cultural works or academic efforts based on the behavior or unconventional political beliefs of an artist, author, or musician, or the taste of an infamous person who loved a certain work.

Circumstantial

Ad hominem circumstantial points out that someone is in circumstances such that they are disposed to take a particular position. Ad hominem circumstantial constitutes an attack on the bias of a source. This is fallacious because a disposition to make a certain argument does not make the argument false; this overlaps with the genetic fallacy (an argument that a claim is incorrect due to its source).

The circumstantial fallacy applies only where the source taking a position is only making a logical argument from premises that are generally accepted. Where the source seeks to convince an audience of the truth of a premise by a claim of authority or by personal observation, observation of their circumstances may reduce the evidentiary weight of the claims, sometimes to zero.

Examples:

Mandy Rice-Davies's famous testimony during the Profumo Affair, "Well, he would [say that], wouldn't he?", is an example of a valid circumstantial argument. Her point was that a man in a prominent position, accused of an affair with a callgirl, would deny the claim whether it was true or false. His denial, in itself, carries little evidential weight against the claim of an affair. Note, however, that this argument is valid only insofar as it devalues the denial; it does not bolster the original claim. To construe evidentiary invalidation of the denial as evidentiary validation of the original claim is fallacious (on several different bases, including that of argumentum ad hominem); however likely the man in question would be to deny an affair that did in fact happen, he could only be more likely to deny an affair that never happened.

Conflict of Interest: Where a source seeks to convince by a claim of authority or by personal observation, identification of conflicts of interest are not ad hominem – it is generally well accepted that an "authority" needs to be objective and impartial, and that an audience can only evaluate information from a source if they know about conflicts of interest that may affect the objectivity of the source. Identification of a conflict of interest is appropriate, and concealment of a conflict of interest is a problem.

Ad feminam/Ad hominem

An ad feminam is an ad hominem attack, used in attempt to defeat a woman's argument. An example would be the response "Is it your time of the month?" to a woman making an argument. The term is most frequently used in this sense in feminist philosophy, to note systemic tendencies to discredit opinions of women. As such, it is similar in nature and purpose to such feminist neologisms as "herstory". Quotes:

• "Ahmad's characteristic method here of reductive ad hominem and ad feminam critique subverts his accompanying claim to Marxist subjectivity..."
• "Almost any ad hominem (or in this case, ad feminam) response such as this one invalidates the content of the patient's viewpoint"

In Latin, the word homō (of which hominem is the accusative case) has the gender-neutral meaning of "a human being", "a person" (unlike the words in Romance languages it gave rise to, such as French homme and Italian uomo). A translation of ad hominem that preserves this gender-neutrality is "to the person". In contrast, ad feminam is gender-specific and used to describe attacks on women as women or because they are women.

Tu quoque

Main article: Tu quoque

Ad hominem tu quoque (literally: "You also") refers to a claim that the source making the argument has spoken or acted in a way inconsistent with the argument. In particular, if Source A criticizes the actions of Source B, a tu quoque response is that Source A has acted in the same way. This argument is fallacious because it does not disprove the argument; if the premise is true then Source A may be a hypocrite, but this does not make the statement less credible from a logical perspective. Indeed, Source A may be in a position to provide personal testimony to support the argument.

For example, a father may tell his son not to start smoking as he will regret it when he is older, and the son may point out that his father is or was a smoker. This does not alter the fact that his son may regret smoking when he is older.

Guilt by association

Main article: Association fallacy

Guilt by association can sometimes also be a type of ad hominem fallacy if the argument attacks a source 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:

1. Source S makes claim C.
2. Group G, which is currently viewed negatively by the recipient, also makes claim C.
3. Therefore, source S is viewed by the recipient of the claim as associated to the group G and inherits how negatively viewed it is.

Halo effect

See also; List of cognitive biases

Ad hominem arguments work via the halo effect, a human cognitive bias in which the perception of one trait is influenced by the perception of an unrelated trait, e.g. treating an attractive person as more intelligent or more honest. People tend to see others as tending to all good or tending to all bad. Thus, if you can attribute a bad trait to your opponent, others will tend to doubt the quality of their arguments, even if the bad trait is irrelevant to the arguments.

Questions about the notion of an ad hominem fallacy

Doug Walton has argued that ad hominem reasoning is not always fallacious, and that in some instances, questions of personal conduct, character, motives, etc., are legitimate and relevant to the issue, as when it directly involves hypocrisy, or actions contradicting the subject's words.

The philosopher Charles Taylor has argued that ad hominem reasoning is essential to understanding certain moral issues, and contrasts this sort of reasoning with the apodictic reasoning of philosophical naturalism.

See also

• And you are lynching Negroes
• Appeal to authority
• Association fallacy
• Character assassination
• Credibility
• Discrediting tactic
• Fair Game (Scientology)
• Fundamental attribution error
• Hostile witness
• List of logical fallacies
• Negative campaigning
• Poisoning the well
• Reputation
• Self-hating Jew
• Shooting the messenger

Further reading

• Hurley, Patrick (2000). A Concise Introduction to Logic (7th ed.). Wadsworth. pp. 125–128, 182. ISBN 0-534-52006-5. 
• Copi, Irving M.; Cohen, Carl. Introduction to Logic (8th ed.). pp. 97–100. 
• Walton, Douglas (1998). Ad Hominem Arguments. Tuscaloosa: University Alabama Press. 

External links

• Ad hominem at PhilPapers
• Nizkor.org: Fallacy: Ad Hominem.
• Nizkor.org: Fallacy: Circumstantial Ad Hominem.
• Argumentum Ad Hominem
• University of Winnipeg: Argumentation Schemes and Historical Origins of the Circumstantial Ad Hominen Argument PDF (70.2 KB)
• Logical Fallacies: Ad Hominem
• Mission Critical: Introduction to Ad Hominem Fallacies