Saturday, November 17, 2007

Moving goalposts

As I said before, I think it's important that we not blindly apply logical fallacies as if they were infallible. Well the "moving goalposts" fallacy is one that I think should not be considered a fallacy at all, though for different reasons from the previous examples. Most skeptics would disagree with me, so I'll argue my point.

The "moving goalposts" fallacy starts out when, in a debate between Alice and Bob*, Alice sets a "goalpost" for Bob. Alice says, "If you can do X, you will have proven me wrong." Bob proceeds to do X. Alice seems to forget what she had previously said, and now says, "If you can do Y, I will eat my words." Bob proceeds to do Y. Alice again seems to forget, and now says, "If you can do Z, I will put my foot in my mouth." Bob becomes frustrated and gives up.

The idea behind this fallacy is that even though Bob has disproven Alice's claim twice, Alice does not recognize that she has lost. If action X does in fact disprove Alice's claim, and if Alice does not change her claim, then, yes, Alice is in the wrong. She is also in the wrong if she merely changes the name of her claim, or otherwise equivocates what she really thinks. She is doing the rhetorical equivalent of sticking her fingers in her ears and singing loudly, "I know I'm right and you're wrong because I haven't heard any evidence!"

But I think that in practice, this is not what usually happens. In practice, Alice changes her position. Her change in position may have been very slight, and implicit, but it is a change nonetheless. Perhaps she has decided that X does not in fact disprove her original claim. Other times, Alice may change her original claim slightly to accommodate the evidence from X. I do not see why changing one's own position should be considered in itself fallacious.

However frustrated Bob may be, he must provide a new argument against Alice's new claim. Either that, or Bob may point out that his previous arguments still apply to Alice's new claim. There are innumerable wrong positions Alice could take. Must Bob counter every single one that Alice decides to take? Yes, at least if Bob wants to convince Alice. Perhaps he can think up an argument that counters all possible positions Alice could take.

I think what people really find frustrating about moving goalposts is that they want their opponent to definitively lose. Bob wants Alice to publicly admit complete defeat. But instead of admitting defeat, Alice merely decides to replace her old claim with a new, slightly different one. But I would say that the desire for a clear surrender is an emotional one. In a way, Alice has admitted defeat by discarding her old position. She just hasn't done it loudly or theatrically. They seem to fantasize about their opponents saying, "I was a fool, and you are wise." Take what you can get, I say. The real goal of debate isn't victory, it's truth.

Rather than just talking about Alice and Bob, allow me to substitute a real life example. Many people think of "Intelligent Design" as being Creationism with a moved goalpost. Well, I think that means you can't always use the same arguments against the two. On the one hand, you could argue against both ID and Creationism by pointing out that Evolution is really one of the best established theories in all of science. On the other hand, you couldn't argue against ID by pointing out evidence of a 4.6 billion year history, because (as far as I know) ID already accepts the age of Earth. ID has a ton of problems, but it's still a slight step above Creationism. I just don't see the goalpost-moving as being in itself fallacious. Are people not allowed to change their minds, to improve their own positions?

Well, I guess in this case it's reasonable to want a definitive loss, but that's only because ID isn't so much a real debate as it is a silly PR machine.

*In case it isn't clear, Alice and Bob are just two names I am using to represent any two people in a debate. Physicists seem to be fond of using these two particular names in thought experiments, so I will do the same.

8 comments:

panoramica said...

Moving the goalposts is knowingly evading the issue.
It's defending a position by faith, not reason.
One can't argue or discuss with faith; faith is an shakeable rock against which logic and facts swirl. An infinite progression (?); why bother? Hotdogs at least are real ...

miller said...

Yes, it can be that, or it can be a legitimate change of mind. How do we tell the difference? Not by painting every such situation with a broad brush.

panoramica said...

I used the word 'infinite'.
One has to draw the line somewhere, legitimate retrenching only goes so far. Beyond that it is obvious that Bob can never win. Alice isn't advancing the argument, she's slithering out from under; and Bob will never convince her. As you said, she won't listen. She doesn't want to listen or be convinced, and she can evade infinitely by "moving the goal posts".
Of course people are allowed to change their minds, and any concession on the path to Truth is constructive. But evasion is quite different.

Danny said...

I agree with panoramica. One who habitually moves the goalposts to evade refutation is essentially making their position covertly unfalsifiable. Take an example from a recent debate I had with a 9/11 conspiracy theorist. He said that if Osama Bin Laden were really responsible for 9/11, he would be on the FBI's Most Wanted list. Since he's not, he must not be responsible. I pointed out that he was, in fact, on the FBI's Most Wanted list. He then replied that that was just for show, but they're not *really* looking for him. He didn't change or improve his position or his argument, he just slid the goalposts over a bit to the left in order to evade my argument. In my experience, this sort of tactic occurs all the time, and it's useful--and beneficial to the neutral observer--to be able to call "bullshit" instead of just continuing to engage every single argument they throw at you as if they're being perfectly forthright.

miller said...

I admit that moving goalposts can be fallacious. My point was that it's not always the case. Where do you draw the line between just a few changes of mind and habitual goalpost moving? If it happens twice? Three times? More? I hate to put a quota on how many times people can change their minds.

I tend to think that people are honestly fooling themselves rather than knowingly trying to fool everyone else. Perhaps it's because I usually deal with a different sort of crowd? Or maybe I'm just hopelessly idealistic and naive.

Maybe, as in your example, we should define "goalpost moving" to be a move to the side, without any real improvement. That would be a good distinction.

panoramica said...

For myself it's usually easy to tell who is genuinely discussing and who is moving goal posts. With discussers I discuss, with post movers I graciously concede then get the hell out of Dodge — they're happy, I'm happy; win-win (saves all the aggro).

miller said...

Ha! Yeah, I'm probably obsessing over imagined borderline cases.

Danny said...

"I admit that moving goalposts can be fallacious. My point was that it's not always the case. Where do you draw the line between just a few changes of mind and habitual goalpost moving? If it happens twice? Three times? More? I hate to put a quota on how many times people can change their minds."

I guess, for me, the quality of the change is more important than the number of changes (although inordinately large amounts of spontaneous position changes should raise a red flag). For my money, I'd say it's hard to take seriously any major position change that takes place within the course of a single debate.

If you're having a discussion, and someone proves you wrong, anyone genuinely seeking the truth would say, "You're right; I must reevaluate my position." If they go away and do that and then come back a month later with a different argument, that is all well and good. On the other hand, if someone is proven wrong in a debate and immediately goes into, "Uhhh...well you're still wrong because of this!" mode, it's a good sign that they're not being genuinely intellectually rigorous. They are defending their own flawed position to the death by any means they can find to do so. That's not the way critical thinking works.