Don't accept blurry arguments

People often use blurry arguments, which vacillate between two interpretations: one which is plausible but uninteresting, and one which is interesting but implausible.* For instance, consider “killing is killing” uttered in the context of abortion. On a literal interpretation, killing is identical with itself, which is true but uninteresting. On the other interpretation, abortion is just as bad as, e.g. a murder of an adult human, which is a more interesting but much less plausible claim. Blurry arguments can be rhetorically effective, since the first interpretation makes them appear plausible, while the second interpretation makes them appear interesting. But of course from a logical point of view you can’t jump around between interpretations in this way, but have to choose one. Blurry arguments are thus akin to the classic quote:

Your manuscript is both good and original; but the part that is good is not original, and the part that is original is not good.

Nevertheless, blurry arguments involving hyperbole, deepities, motte-and-baileys, or poor metaphors and analogies are very common in debates and discussions. (E.g. see my posts on hyperbole and motte-and-baileys.)

How should we deal with them? What attitude should we have towards them?

My view is that when we’re discussing serious topics, then we should effectively call them out. We should either simply stick with the literal interpretation - and refuse, e.g. to accept the retreat to the motte (“that’s not what you said”) - or directly point out the ambiguity (“this argument is ambiguous between two interpretations, one of which is uninteresting, and one of which is false”).

At times, this may make it look like you’re being overly literal-minded, and fail to understand how language works. It may also make you appear rude and socially insensitive. These are definitely factors to take into consideration, but at the same time, we can only give them so much weight relative to the main aim of serious discussions - to arrive at the truth. Exactly how to weigh these factors against each other must be decided on a case-by-case basis, but in general my view is that in effective altruist and rationalist circles, we shouldn’t be too accommodating of blurry arguments.

* The idea is from an excellent post (I recommend reading it in full) by Ben Garfinkel, but he rather uses the term “blurry sentence”. Blurry sentences are used in a variety of contexts, including literature (literary metaphors like “his heart skipped a beat”) and innocent puns, as well in political and philosophical arguments. I’m just focusing on the latter in this post. Using blurry sentences playfully in less serious contexts seems unproblematic.