Selective Sampling

I think that Donald Trump is really dangerous.

Here are some true facts.* These facts include moderately detailed descriptions of sexual assaults—skip past the bullet list if you like; the relevance of these facts will be explained below.

• In 2008, a 54-year-old New York man named Donald Bowen traveled to Texas in order to pursue a sexual relationship with a 14-year-old boy he'd been grooming on the internet.
• In 2009, another New York man, one Donald Caban, was convicted of molesting multiple teenage girls in his home over several decades.
• Donald Darwell, of New York, is a convicted rapist. In 1978 he forcibly raped a woman at knifepoint. She was badly injured in the attack, and was unable to work for nearly a year.
• In 2006, New Yorker Donald Valentine was convicted on two counts of sexual assault. His victim was a 16-year-old mentally disabled girl.
• Donald Brown, a 42-year-old New York man, was apprehended in the act of the attempted rape of a 10-year-old boy whose parents had left him in his care.
• 55-year-old Donald Glenn, of New York, convinced a reluctant acquaintance to go out on a date with him. That night, he overpowered and choked her before raping her both vaginally and anally.
• Donald Jones struck a female stranger with his fist in 1993, then held her at gunpoint and attempted to rape her. When she screamed, passers-by stopped and he fled, before being caught by police and convicted of first-degree attempted rape.

([*] These are not quite facts, but they're close. In the interest of privacy, I have changed the surnames of these individuals. Importantly, I have left all of their given names unchanged. I've embellished these stories slightly, to give a bit more detail to hang on them. (I did this for vivacity, and to make the fallacy more tempting. I didn't have easy access to the actual details, or I would have used them.) I found these facts via the New York State Criminal Justice Services website.)

Knowing about Sexual Assault, Having Enough Evidence, and the Contextualist Fallacy

Last week I wrote an op-ed in the Vancouver Sun about university sexual assault policies. One of the things I tried to do there was to draw a connection between some of the questions in that area and my own research into knowledge and contextualism. I tried to make the case that a kind of contextualist fallacy lies behind some attitudes about university sexual assault policies. I still think that's plausible and interesting, although there are certainly competing possible explanations. But a tweet I received in response definitely commits the contextualist fallacy.

The contextualist fallacy is the failure to attend to the context-sensitivity of language, allowing for the construction of a superficially apparently-valid argument that is in fact fallacious. For example, the word 'now' is context-sensitive. Sometimes when it is used, it refers to 9:47 am Monday, Jan 18. (In fact, that's the time that word refers to when I utter it right now.) Here is a true sentence:

1. It is before 10:00 Monday right now.

Actually, although it is before 10:00, it's not very far before 10:00, when I have to teach. So I'd better come back and finish this post later.

Hypocrisy, Self-Defeat, and other Ad Hominem Arguments

You learn in intro-level critical thinking to distinguish criticizing a position from criticizing a person holding a position. Doing the latter is an ad hominem argument. (The latin literally means 'to the person'.) In this dialogue, Frank makes an ad hominem argument:

Jill: The minimum wage should be higher. It is important that employees be able to make a living wage, and economic studies indicate that raising the minimum wage will probably not significantly reduce employment.
Frank: Jill often keeps her library books past the due date. Don't listen to her, the minimum wage is fine as it is.

This is a really blatant ad hominem; Frank is ignoring Jill's argument, and instead saying something about Jill herself—in this case, something completely irrelevant. But one can have ad hominems without this kind of irrelevance, as in this version of the case:

Jill: The minimum wage should be higher. It is important that employees be able to make a living wage, and economic studies indicate that raising the minimum wage will probably not significantly reduce employment.
Frank: Jill works a minimum-wage job, so her motives aren't pure. The minimum wage is fine as it is.

This version is less off-the-wall—one can actually imagine Frank arguing in this way—but it's also pretty clearly an ad hominem. Frank has ignored the argument Jill made, and is instead focusing on Jill herself.

Argumentum ad hominem is typically recognized as an argumentative fallacy. Perhaps sometimes it's appropriate to argue about the person—perhaps, for example, in some electoral cases, one of the main questions we're interested in is what kind of a person is this?. But establishing something bad about a person making an argument is not to be confused with arguing against the conclusion. So much is, I think, pretty much obvious, once it's spelled out. But there are at least two kinds of cases where ad hominem arguments can be misleadingly tempting.

Consider arguments involving hypocrisy. Someone is hypocritical when one condemns behaviour of which one is oneself guilty. When Newt Gingrich got all high-and-mighty about Bill Clinton's marital infidelity while at the very same time carrying on with a secret affair, that was hypocrisy. When people are guilty of hypocrisy, it can feel pretty satisfying to call them out for it—it's a strong rhetorical move. But it's also argumentum ad hominem. It says something about the person making the argument, rather than about the argument or conclusion itself.

Jill: The minimum wage should be higher. It is important that employees be able to make a living wage, and economic studies indicate that raising the minimum wage will probably not significantly reduce employment.
Frank: Jill doesn't really care about people making a living wage—her company profits tremendously from underpaying its employees.

Frank may succeed in getting people not to listen to Jill with this argument, but he does so in a way that totally ignores the content of what she actually said. Her argument is about what employees need and the relationship between minimum wages and unemployment. Frank has totally ignored that argument, and focused on Jill instead. That's the definition of ad hominem. If you don't care about Jill and only want to know what to think about the minimum wage, Frank's argument is just a distraction. Accusing people of hypocrisy is ad hominem.

The same goes, I think, for at least some self-defeat arguments. In my introductory epistemology course this week, we're discussing radical skepticism—the view that nobody knows or has any reason to believe pretty much anything. (Think about all the possible ways any of your beliefs could be wrong—you could even be a brain in a vat!) One charge people often level against this view is that it is self-defeating in the following sense: no skeptic can coherently claim to know, or have reason to believe, that skepticism is true. One imagines winning an argument with a skeptic, perhaps along lines like these:

Jill: Nobody knows anything. After all, it's possible to be deceived about any possible belief.
Frank: Jill can't possibly know what she's talking about, because if she did, then that would be some knowledge someone has.

Frank's argument is clever, and he might even convince people not to listen to Jill. But his argument is ad hominem. He says that Jill is being inconsistent in a certain kind of way, not that the content of her view is. Jill has given an argument having to do with the possibility of error—the argument does not depend on there being any individual who can coherently endorse it. Frank has ignored Jill's argument, and attacked Jill herself. That's the definition of an ad hominem argument.

One difference between this last kind of ad hominem and more prototypical cases is that it doesn't depend on particular contingencies of Jill's—there's a kind of argument template that one could use against any skeptic. But that's just to say that one is prepared to give an ad hominem argument against anyone who thinks radical skepticism is true. But this isn't an argument against radical skepticism itself.

Here is a coherent hypothesis: nobody knows anything. Arguing that nobody could know it is a very different thing from arguing that it's false. The self-defeat argument only does the former; it is ad hominem.