2013-11-06

A Bad Argument Isn't A Personal Attack

The set of bad arguments includes the set of personal attacks, i.e. "arguing from ad hominem." But the set of ad hominem attacks does not include the set of bad arguments. In other words, only some bad arguments are personal attacks; only some personal attacks also happen to be bad arguments.

An ad hominem logical fallacy goes like this:
Smith: Single-payer health care systems are so costly to manage that they result in a lower quality of care for all patients.
Jones: Smith is an evil man who wants to deprive the poor of health care!
In case you missed it, it was Jones who engaged in an ad hominem attack against Smith. Rather than arguing against Smith's point, Jones sought to establish Smith as a villain. (There is also an implied genetic fallacy in that there is no reason villains are automatically wrong, but that's a valid blog post in its own right.)

Now let's absolve Jones of his sins and give him a second go at it:
Smith: Single-payer health care systems are so costly to manage that they result in a lower quality of care for all patients.
Jones: Saying single-payer systems are costly is like saying French fries are costly.
Here's a question for you: Which logical fallacy did Jones just commit?

If you guessed, "None," you're absolutely right. What Jones said didn't make a lot of sense. At best, it was a bad analogy. It was a poor argument. No one would be convinced to adopt a single payer health care system on the strength of Jones' argument alone. But it wasn't a fallacy.

Okay, clean slate again. Let's give Jones a third chance to argue his case:
Smith: Single-payer health care systems are so costly to manage that they result in a lower quality of care for all patients.
Jones: Saying single-payer systems are costly is like saying French fries are costly.
Smith: That's just so typical of you, Jones. I might have known you'd resort to ad hominem attacks.
Once again, we know that Jones did not commit any logical fallacies, even though his argument is terrible. But what do we make of Smith's claim?

We might empathize with Smith since, after all, Jones' argument is among the worst I have ever seen in favor of single-payer health care. But how could we possibly agree with Smith that Jones "resorted to ad hominem?"

In the heat of a debate, it's often tempting to proclaim that the other side has resorted to ad hominem. I presume that one of the reasons this claim is tempting is because logical fallacies - when committed in earnest and actually detected - are invalid arguments. Invalid arguments are easy to defeat precisely because they are invalid. But simply declaring an argument to be fallacious or invalid does not actually make it so.

Likewise, declaring something to be a personal attack when in fact it's really just a bad argument is... well, befuddling. It's like accusing the waiter of murder when what you really mean is that you'd like side of croutons.

No offense intended in that last sentence, by the way. It may be a bad analogy, but it's not a personal attack.