I’ve used this approach in debates online. People like to assert things without evidence or even bothering to craft a proper argument. This is no doubt because, to them, the proof of their claim is self-evident. Everybody knows X is true.
When challenged about X, they then rely on what I call “copy & paste” arguments — or what Weiss calls “headlines and talking points.” Her suggested challenge is a clever next move: In your own words, prove it.
What’s nice about this move is it bypasses the typically inevitable exchange of “facts.” As the saying goes, “you are entitled to your own opinion but not your own facts.” Except: Everyone collects their own facts anyway, and many debates devolve into fighting over whose facts are correct. “Prove it” alone would invite this sort of pointless back-and-forth. Everyone has a ready supply of “sources” that back up their beliefs.
No, you asked them to prove it in their own words. How do they do that? Well, they have to craft a cohesive argument (i.e. go deeper than headlines and talking points) AND subject their reasoning to the laws of logic. This is the arena where silly thinking is easily exposed and people become much less sure of themselves. This is where filter bubbles burst and people find middle ground.
Or not. Persistence of illogic is too common a thing. My belief is that it’s only outward, though. Inside, illogic made plain sticks in people’s minds like a stone in their shoe (HT: Greg Koukl). When no one is looking on, they work to get it out — and that can change minds over time.