Difference between revisions of "ad hominem"

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An ad hominem (Latin: "to the man"), also known as argumentum ad hominem, is an attempt to link the validity (WP) of a premise (WP) to a characteristic or belief of the person advocating the premise.^[1] The ad hominem is one of the logical fallacies recorded by the Greeks a classic fallacy (WP) of logic.^[2]

In law (WP), questions of personal conduct, character, motives, etc., are allowed as evidence.^[3] This does not make it less of a logical fallacy. For this reason and others there is a considerably lower standard of evidence in law than there is in formal logic.

History

Ad hominem had its roots in works of Aristotle, the Greek philosopher. Gabriël Nuchelmans holds that there are separate and distinct strands of meaning that have proceeded throughout history from Aristotle.^[4] The first two of these describe positive steps that can be taken in a logical argument, but are nonetheless concerned with responding to a qualities of another person, namely their points of view.^[4]

One type emanates from Aristotle's own peirastiko logoi, one of his four types of arguments (with dialectical, doctrinal or demonstrative, and eristic) which proposes that arguments be confined within the compass of the respondent's knowledge and views. Thus, paraphrases Nuchelmans, "we shall be able to converse with them setting out, not from views that others hold, but from their own views" This "peirastic" argument was called "disputatio temptativa" in Latin.^[4]

Another describes the process of directing arguments at points that had been conceded by another. Thomas Aquinus decided, in reading Aristotle's Physics, that it was not possible to provide a logical proof (Formal proof) (WP) for someone who denied a principle (WP) used as a premise of that proof; however, it was possible to prove something based on principles they believed or accepted.^[4]

Aquinus' process is slightly more concerned with directing arguments than simply engaging in them efficiently, and the later developments of ad hominem changed slightly in the same way, past responding e concessis, which itself started as arguing within another's points of concession and became arguing using conceded points whether or not they had merit. It is very tempting to attribute this prevalence of tactics over ethics to Rhetoric; while logic concerned itself with building roads along the journey of argumentation, rhetoric sought the quickest path to a single destination: winning.^[4]

The development of this more rhetorical type of ad hominem began to be criticized as purely expedient and to be avoided, in the 16th and 17th centuries. More concretely, Arnold Geulincx in the 17th C showed how Wikipedia:Reductio ad absurdum was applied to others' arguments for another kind of ad hominem. At the same time, the e consessis and rhetorical varieties of ad hominem began to be conflated, until the modern, negative meaning became the sole survivor in common usage.^[4]

Types

Abuse

Ad hominem abuse (WP) (also called personal abuse or personal attacks) usually involves Wikipedia:insulting or belittling one's opponent in order to invalidate his or her argument, but can also involve pointing out ostensible or even factual character flaws or actions. This tactic is logically fallacious because the source of an argument is not the argument.

Examples:

• "You can't believe Jack 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."

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 Wikipedia:genetic fallacy (an argument that a claim is incorrect due to its source).^[5]

The circumstantial fallacy only applies 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.^[6]

Examples:

Wikipedia:Mandy Rice-Davies's famous testimony during the Wikipedia:Profumo Affair, "Well, he would [say that], wouldn't he?", is an example of a valid circumstantial argument. Her point was that since a man in a prominent position, accused of an affair with a Wikipedia: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: Wikipedia:Tu quoque

Ad hominem Wikipedia:tu quoque (lit: "You too!") 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: Wikipedia: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.^[7]

This form of the argument is as follows:

Source S makes claim C.

Group G, which is currently viewed negatively by the recipient, also makes claim C.

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 Wikipedia:verbal abuse or "name-calling" itself is not an ad hominem or a logical fallacy.^{[8][9][10][11][12]}

This is not to be confused with a true fallacy, which would be "X is idiotically ignorant [of politics], so why should we listen to him now?"

Identification of conflicts of interest - see "Circumstantial", above.

See also

References

Further reading

• Wikipedia:Patrick Hurley (2000). A Concise Introduction to Logic, Seventh Edition, p. 125–128, 182, Wikipedia:wadsworth, a division of Wikipedia:Thompson Learning.
• Copi, Irving M. and Cohen, Carl. Introduction to Logic (8th Ed.), p. 97-100.
• Wikipedia:Doug Walton (1998). Ad Hominem Arguments, p. 240 pp, 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 Argument 70.2 KB application/pdf, 71948 bytes
• About.com: Argument Against the Person (Argumentum ad hominem)
• Logical Fallacies: Ad Hominem
• Infidels.org: Logic and Fallacies: Constructing a Logical Argument (Argumentum ad Hominem)
• Mission Critical: Introduction to Ad Hominem Fallacies

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