13. Introduction to Ad Hominem Fallacies
Wireless Philosophy, Fallacies, 6:39. Original title: CRITICAL THINKING - Fallacies: Introduction to Ad Hominem Fallacies
Summary
Julianne Chung (Yale University) introduces ad hominem fallacies ("to the man", or more descriptively "against the person"), also called fallacies of personal attack: they are committed whenever someone challenges a position by criticising something about its source, shifting attention away from the argument and onto the person making it. She surveys six varieties.
Abusive and circumstantial ad hominem
Abusive ad hominem arguments present someone's personal characteristics as good reason to discount their ideas, for instance: "We should never think that anything politicians ever say is true, because they're all dirty, lying scumbags." Even the least admirable people say true things at least some of the time, so such characteristics do not affect the merits of a claim considered on its own.
Circumstantial ad hominem arguments instead challenge a position by suggesting the person advances it merely to serve her own interest, focusing on situation rather than character: "Summer vacation should be abolished. Any student who argues otherwise should not be listened to, because he or she stands to benefit from its continuation." Whether someone benefits from her own conclusion has no bearing on whether that conclusion is right; plenty of excellent arguments also happen to benefit those making them.
Tu quoque and guilt by association
Tu quoque ("you too") accuses someone of acting in a way that contradicts the position she supports, and concludes her view is worthless because she fails to follow her own advice: "I can't believe you're trying to convince me that I should give more money to charity, when you don't give nearly as much as I do." Whether the arguer is herself consistent has no bearing on whether the other person should give more; that depends on other things, such as income and current giving.
Guilt by association argues against a view by pointing out that some unsavoury person is likely to agree with it: "Chocolate chip cookies can't be any good. My philosophy professor loves them, and she is the meanest teacher I have ever had!" A claim can be true regardless of who endorses it.
Genetic fallacy and ad feminam
The genetic fallacy casts a claim into doubt by condemning its origin rather than the person who currently holds it: "The founder of organization X served time in prison for embezzlement, so we can conclude that the organization must still be corrupt." Chung notes that things could have changed since an organisation's founding, and that the genetic fallacy can also be used positively, to support a claim by praising its origin.
Ad feminam arguments discredit a claim on the grounds that a woman proposed it, of the form "Why should I believe anything you have to say? After all, you're just a woman." Chung takes it to be more or less obvious why such arguments are deeply problematic.
Key takeaway
Chung closes by putting a further example to the viewer, "Ronald Reagan was in favor of similar policies, so they must be the right thing to do", and asking which fallacy it commits: recognising these six patterns, and separating an arguer's character, circumstances or origin from the merits of the claim itself, is a skill that takes practice.