January 04, 2015 at 06:26PM [via Facebook]
Sidebar. Being able to describe an argument as having a “motte-and-bailey” structure is not actually a refutation of the argument you’re characterizing that way.
Lots of good arguments involve noting a weaker claim and a stronger claim; so do lots of bad arguments. In real world arguments people will often go back and forth between an argument on the weaker claim and an argument on the stronger claim because their interlocutor reacts to the stronger claim in ways that don’t seem rationally defensible; so the weaker claim is brought up to serve as a kind of sanity check before going back to the argument about the stronger claim. Now the interesting question in all this is whether your interlocutor is moving from the weaker to the stronger by means of a cogent argument (in which case what they’re doing isn’t fallacious at all), or moving from one to the other without further argument (in which case what they’re doing is begging the question), or just actually equivocating between the weaker claim and the stronger claim. If the last, then of course they are committing a fallacy. (To wit, the fallacy of equivocation.) But to show they are doing that, you’ve got to actually engage with and criticize the argument, not just characterize it as involving a weaker claim and a stronger one.