How did Mitt Romney first find out about the 9/11 attacks? As Buzzfeed notes, he's told two versions of this tale: in one, he's giving a radio interview when a host interrupts to tell him the news; in the other, someone rushes into his office to inform him. Just to be explicit: this really doesn't matter very much. As with so much about Willard, it's a little weird, since most people can remember exactly where they were. (I was at my desk in London, researching an article about Bob the Builder, since you asked.) But as an example of his complicated relationship with the truth, it was minor, and quickly dwarfed by his campaign's attempt to argue that a statement issued by the US embassy in Cairo, prior to yesterday's violence, was actually a response to it.

Still, the 9/11 discrepancy helped clarify something I'd been finding especially aggravating about this election campaign so far. We've heard much talk about truth and lies and the "post-truth campaign", fuelled by the controversial role of fact-checking operations like Politifact and FactCheck.org. (Here on CiF, last week, Bob Garfield argued that the Republicans are increasingly taking refuge in the "medium lie", too inconsequential to cause a fuss.) But something's missing from this conversation. What this campaign has been especially full of, so far, is bullshit.

In his 2005 bestseller, On Bullshit, the Princeton philosopher Harry Frankfurt made a crucial distinction between lies and bullshit. To lie is to intentionally deceive, by saying what you know (or believe) isn't the truth. Romney does this all the time. To bullshit, though, is to talk without regard for the truth, one way or the other. The liar and the truth-teller, writes Frankfurt, "are playing on opposite sides, so to speak, in the same game"; the bullshitter, by contrast, refuses to play. "He does not reject the authority of the truth, as the liar does, and oppose himself to it. He pays no attention to it at all."

Frankfurt has much more to say – I'm shamelessly ripping his concept out of its context here – but applying it to recent pronouncements is illuminating. Does anyone really believe, for instance, that Romney has a sinister reason for telling two stories about 9/11? Or that Paul Ryan decided to tell a calculated lie about his marathon times? Or that he was consciously telling the truth or lying about his mysterious mountaineering record, pored over by James Fallows? Or that Romney was lying, in the Frankfurtian sense, when he denied having seen Super Pac ads made in support of him, then said he'd seen them? Or, to disinter an old classic, when he idly spoke of having been a hunter all his life, but turned out not to have been? Is it because of "lies" that we'll never know whether Seamus the Roofrack Dog, of celebrated legend, was in "an air-tight container", or that his excrement spilled down the side of the car, both of which presumably couldn't be true at the same time? (Also: who even thinks about putting a dog in an air-tight container?)

Of course not. These incidents all involve candidates emitting words from their mouths, in roughly grammatical order, to sound plausible, as circumstances demand. These statements aren't the truth, nor a deliberate attempt to evade the truth. They're pure bullshit.

And there is a reason why most of those examples involve "soft" questions about the candidates' hobbies and biographies, by the way: that's when bullshit's easiest to spot (smell?). On more important topics, it's harder to distinguish bullshitting from lying, because it's difficult to imagine that someone running for the presidency or vice-presidency of the United States might really make nakedly untrue claims about his opponent's healthcare policies, or about major episodes in American history, out of anything other than coldly calculated intent.

But I wonder. Through "excessive indulgence" in bullshitting, Frankfurt writes, "a person's normal habit of attending to the ways things are may become attenuated or lost". Bullshitting breeds bullshitting. And ultimately, that's worse than lying, Frankfurt argues: at least liars remain in some kind of relationship with the truth.

And so the politicians with integrity keep telling the truth, the liars keep lying, the fact-checking operations keep adjudicating between them, and the pundits keep worrying about lies. But none of this troubles the bullshitter, who exists in another dimension entirely, bullshitting happily away. You think he cares about adhering to the truth, or carefully concealing his divergence from it? Bullshit.