A DOCTOR tells her patient to lose weight, and the patient thinks: If my doctor really believed that, she wouldnt be so fat. A movie aficionado pans the latest Tom Cruise flick because Cruise is a Scientologist. A homeowner ignores a neighbors advice on lawn care because the neighbor is a ... you name it: Democrat, Republican, Christian or atheist. These examples illustrate classic uses of ad hominem attacks, in which an argument is rejected, or advanced, based on a personal characteristic of an individual rather than on reasons for or against the claim itself.

Putting the focus on the arguer or person being discussed can distract us from the issues that matter. Rather than concentrating on an individuals character, we should, in these cases, be asking ourselves questions such as, Is the doctors advice medically sound? Is the Cruise film entertaining? Is the neighbors lawn healthy? Meanwhile ad hominem attacks can also unfairly discredit an individual, especially because such critiques are often effective.

Although ad hominem arguments have long been considered errors in reasoning, a recent analysis suggests that this is not always the case. In his new book, Media Argumentation: Dialectic, Persuasion, and Rhetoric, University of Winnipeg philosopher Douglas Walton proposes that fallacies such as the ad hominem are better understood as perversions or corruptions of perfectly good arguments. Regarding the ad hominem, Walton contends that although such attacks are usually fallacious, they can be legitimate when a character critique is directly or indirectly related to the point being articulated.

If Walton is right, distinguishing clearly between these cases is important to evaluating the validity of statements people make to us about others. Good or fair uses of ad hominem critiques should, in fact, persuade us, whereas unwarranted uses should not.

Which ad hominem arguments should we aim to ignore? In the so-called abusive ad hominem, someone argues that because a person has a bad character, we should not accept that persons claims. For instance, during the presidential campaign of 1800, John Adams was called a fool, a gross hypocrite and an unprincipled oppressor. His rival, Thomas Jefferson, on the other hand, was deemed an uncivilized atheist, anti-American, a tool for the godless French. Accusations like these can easily foreclose on intelligent political discourse about what might make either candidate a good president.

Another illegitimate form of the ad hominem is the tu quoque, or you, too version, which is an attempt to discredit a persons claims because the person has failed to follow his or her own advice. The example of the overweight doctor prescribing weight loss falls into this category. Its use is unfair because, after all, there are good reasons for losing weight, and the fact that a doctor has not managed to heed her own advice should not dissuade others from trying to follow it.

The Cruise attack, on the other hand, exemplifies poisoning the well, another brand of ad hominem attacks in which the character assault is launched before the listener has a chance to form his or her own opinion on a subjectin this case, Cruises film. If successful, the reminder that Cruise is affiliated with Scientology will bias the listener against the movie. This partiality is unjustified, because Cruises religious affiliation is not germane to his acting abilities or the entertainment value of his movie.

Fair Use
What types of ad hominems might then be justified? Walton argues that  an ad hominem is valid when the claims made about a persons character or actions are relevant to the conclusions being drawn. Consider, for example, former New York governor Eliot Spitzer, who was caught on a wiretap arranging to hire a prostitute for $4,300. Because this behavior ran counter to Spitzers anticorruption platform, its unveiling would prevent Spitzer from governing successfully; thus, criticizing this aspect of his character was relevant and fair. In an earlier scandal, in 1987, televangelist Jimmy Swaggart was seen at a motel with a prostitute. Because his behavior undercut his preaching and status as a Christian role model, a character attack based on this incident would have been spot-on.

In another case, when President Bill Clinton fibbed on national television about his affair with White House intern Monica Lewinsky, accusations that he was a liar were not entirely unjust. Although a supporter might argue that Clintons sex life was not directly relevant to his ability to govern, his ability to adhere to the truth could certainly be, and his willingness to lie on this occasion could call into question the veracity of his remarks on other subjects.

Of course, we should not discount everything any person says, no matter how badly he or she has been discredited. The fact that a person lies or behaves improperly on one occasion does not mean that he or she lies or behaves inappropriately all the time. Again, a critique of a persons character should not prevent further examination of the arguments at hand. After all, which position is right is usually independent of a persons character or conduct.

Being aware of how the ad hominem attack works can help us evaluate which instances of its use we should ignore and which we should consider. Ask yourself: How relevant is a political candidates character or action to his or her ability to perform in office? How pertinent is any persons past or group affiliation to the claims that person makes or to that individuals expertise in a specific domain? If the character-based attacks are not relevant to these larger issues, then they are best ignored. Instead we should attend to what is really important: What is a person asserting? Why does he or she offer a particular view, and is the view defensible?

This story was originally printed with the title, "Character Attacks".