The Worst Argument In The World

I read the interesting submitted article and its comments right after it was submitted here on Hacker News. The worst argument in the world (a general FORM of argument) is described this way in the submitted article:

"I declare the Worst Argument In The World to be this: 'X is in a category whose archetypal member has certain features. Therefore, we should judge X as if it also had those features, even though it doesn't.'"

This recalls many cases on Hacker News when someone has disagreed with someone else by saying, "Your argument is an example of [name of rhetorical or logical fallacy]." Perhaps it is carrying out the worst argument in the world to identify one part of someone's statement as a logical fallacy, if the fallacy doesn't vitiate the statement, and if sound evidence is still in view to support the statement. Sometimes facts of the world are as they are even if they are mentioned by people who argue inaptly, so it would indeed be a bad argument to ignore the message because of infelicities of expression by the messenger. If we look at pg's essay "How to Disagree,"

http://www.paulgraham.com/disagree.html

we see advice that a better way to disagree is

"Refuting the Central Point.

"The force of a refutation depends on what you refute. The most powerful form of disagreement is to refute someone's central point."

So I guess my central point here [smile] is that while it may be interesting to identify a general form for many particularly bad arguments, it is even better to be specific in grappling with the evidence for the core factual assertions of the person with whom you disagree. That takes abundant knowledge of the world, and a willingness to look up facts. I always appreciate people on Hacker News who can point to carefully gathered facts, analyzed by people with appropriate domain-related knowledge, as we discuss issues here.

Slighty more reasonable, but perhaps more insidious is the "slippery slope" argument. So the first example, about Martin Luther King being a criminal - could be more subtly argued by saying something like "well obviously he doesn't count, but where do we draw the line between 'good' criminals and 'bad' criminals, and invoking slippery slopes. Then the argument ends up basically being the same, but seems on the surface to be less dogmatic.

Certainly some slippery slope arguments are good, though!

For instance, suppose a terrorist starts demanding a large sum of money not to blow up a plane. Suppose also that the direct risk-corrected value of the plane, even excluding passenger lives, also exceeds the price the terrorist is asking for. We still make it policy not to negotiate with the terrorist, because doing so would create a positive feedback loop that pushes us down a slippery slope.

When you think about it, it's a fairly insidious argument to say that slippery slope arguments should be rejected because they fall into a category of arguments that are subtle and hard to refute because they are so insidious. An amusing implied prior of the slippery slope fallacy is that once we start accepting valid slippery slope arguments, what's to stop us from accepting the really terrible ones that take the same structure?

I think pointing out a logical fallacy is not a refutation. Rather than saying "your argument is wrong", it says "your argument is not well-formed". This is much like the difference between a program that has a bug and a program that has a parse error.

To take the most glaring example: "my point is true because my point is true". Obviously, nobody actually says this seriously. But some arguments are isomorphic to this. And any argument like that is not wrong per se--it is literally meaningless.

Other fallacies are more subtle and complicated, but the idea remains the same: using a fallacy does not invalidate your point but merely renders your argument meaningless. I can say that "the sky is blue because everybody says so" and I would not be wrong--given the sky is actually blue, of course--but the argument would still be a fallacy. I think to point this out is valuable even (perhaps especially) if you do not disagree with the point in question.