Ad hominem

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

An ad hominem (Latin for "to the man" or "to the person"), short for argumentum ad hominem, is an attempt to negate the truth of a claim by pointing out a negative characteristic or belief of the person supporting it.^[1] Ad hominem reasoning is normally described as a logical fallacy.^[2][3][4]

Halo effect

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.

Types

Abusive

Abusive ad hominem (also called personal abuse or personal attacks) usually involves insulting or belittling one's opponent in order to attack his claim or invalidate his argument, but can also involve pointing out factual but apparent character flaws or actions that are irrelevant to the opponent's argument. This tactic is logically fallacious because insults and negative facts about the opponent's personal character have nothing to do with the logical merits of the opponent's arguments or assertions.

Examples:

• "You can't believe John when he says the proposed policy would help the economy. He doesn't even have a job."
• "Candidate Jane's proposal about zoning is ridiculous. She was caught cheating on her taxes in 2003."
• "What would Mary know about fixing cars? She is a woman." (an example of Ad feminam)^[5]

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.

Examples:

• Jimi Hendrix died of a drug overdose, so his music was worthless.
• Leni Riefenstahl was a Nazi, so her film The Triumph of the Will is devoid of merit.
• Sylvia Plath was a depressive who eventually committed suicide, so her works are unreadable.
• What Ted Kaczynski wrote about boundary conditions in mathematics is shown false due to his crimes.

Circumstantial

Ad hominem circumstantial points out that someone is in circumstances such that he is 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).^[6]

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.^[7]

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 did.

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.

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.^[6]

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.

Common misconceptions

Gratuitous verbal abuse or "name-calling" itself is not an ad hominem or a logical fallacy.^{[7][8][9][10][11]}

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^[12], 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.^[13]

See also

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

References

1. ^ "ad hominem: West's Encyclopedia of American Law". Answers.com. 2007-09-10. http://www.answers.com/topic/ad-hominem. Retrieved 2009-11-08. 
2. ^ Walton, Douglas (2008). Informal Logic: A Pragmatic Approach. Cambridge University Press. p. 190. 
3. ^ Bowell, Tracy; Kemp, Gary (2010). Critical Thinking: A Concise Guide. Abingdon, Oxon: Routledge. pp. 210–213. ISBN 0415471834. 
4. ^ Copi, Irving M. (1986). Informal Logic. Macmillan. pp. 112–113. ISBN 0023249404. 
5. ^ "ad hominem". The American Heritage Dictionary of the English Language (Fourth ed.). 2000 (updated in 2009). http://www.thefreedictionary.com/ad+hominem. 
6. ^ ^{a b} Walton, Douglas (1998). Ad Hominem Arguments. University of Alabama Press. pp. 18–21. ISBN 0-8173-0922-5. 
7. ^ ^{a b} Curtis, Gary N.. "Argumentum ad Hominem". Fallacy Files. http://www.fallacyfiles.org/adhomine.html. Retrieved 2007-09-10. 
8. ^ "Ad Hominem". Plover.net. http://plover.net/~bonds/adhominem.html. Retrieved 2009-11-08. 
9. ^ "Logic Fallacies". The Autonomist. http://theautonomist.com/aaphp/permanent/fallacies.php#adhom. Retrieved 2009-11-08. 
10. ^ "AdHominem". Drury.edu. http://www.drury.edu/ess/Logic/Informal/AdHominem.html. Retrieved 2009-11-08. 
11. ^ "Logical Fallacies» Ad Hominem (Personal Attack)". Logicalfallacies.info. http://www.logicalfallacies.info/relevance/ad-hominem/. Retrieved 2009-11-08. 
12. ^ Walton, Douglas (2008). Informal Logic: A Pragmatic Approach. Cambridge University Press. p. 170. 
13. ^ Taylor, Charles (1997). "Explanation and Practical Reason". Philosophical Arguments. Harvard University Press. pp. 34–60. 

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

• Nizkor.org: Fallacy: Ad Hominem.
• Nizkor.org: Fallacy: Circumstantial Ad Hominem.
• Argumentum Ad Hominem
• the ad hominem fallacy fallacy
• University of Winnipeg: Argumentation Schemes and Historical Origins of the Circumstantial Ad Hominen ArgumentPDF (70.2 KB)
• Logical Fallacies: Ad Hominem
• Infidels.org: Logic and Fallacies: Constructing a Logical Argument (Argumentum ad Hominem)
• Mission Critical: Introduction to Ad Hominem Fallacies