Gordon Brown saved the UK this week.
His 13 minute speech is good in lots of ways, but there are two key strategies he uses right out of argument theory textbooks that put it over the top. It makes a politician dismissed as a zombie years ago suddenly effective as a speaker.
First, he lists 7 arguments the Scottish National Party hadn't answered. Sure, #7 is kind if the same as the first one. Sure, they probably had actually answered his charges, as well. But researchers using the Elaboration-Likelihood Model, which shows how we often process information not with deep thinking but with quick cognitive shortcuts, have shown a strong effect from having a large number of arguments. 7 is a lot.
Second, he invokes the World Wars. And this is where he is genius. He pushes people past the Brave heart "warriot-poet" mythos by invoking other war heroes. He says this:
Aristotle said we need pathos, but he doesn't tell us what heart strings to pluck on. And if any old strings would do, John Edwards would have made it to the White House. Argument theorist Chaim Perelman has argued that you need to give your evidence and reasoning something called "presence." The vision of Allied dead lying side-by-side in their United graves is so powerful, I admit I got a bit misty when I first heard it.
There's a lot of other good stuff in Brown's speech, but these two parts are its rhetorical linchpins.