Donald Trump sailed into the White House on an ocean of lies. His erstwhile political opponent, and then wishy-washy supporter, Sen. Ted Cruz called Trump a “pathological liar.” I take it that a liar becomes pathological when his lies are no longer conscious fabrications, but merely statements made with no regard to truth or falsity. The pathological liar does not circumvent truth; he is oblivious to it. Truth is simply irrelevant to his narrative, which is aimed entirely at creating an emotional response, not at the transmission of information. Actually, in this case perhaps we should analyze the ostensible assertions in such a narrative in much the same way that the emotivists analyzed ethical assertions. “Murder is wrong” looks like an assertion of fact, but the emotivists said that the surface grammar of such ethical utterances is misleading, and that their real purpose is to express emotional responses. Saying “Murder is wrong” is really just a quieter way of saying “Murder! AAAAAHHH!”

Similarly, perhaps, apparent assertions in Trump campaign speeches, such as those claiming that Mexican immigrants are criminals or rapists, should not be taken as assertions at all, but merely as expressions of attitude designed to elicit the same attitude from listeners. In this case, a Trump campaign speech should not really be regarded as a farrago of lies, but as a post-truth narrative. Responding to such a narrative with fact-checking would have the same relevance as quoting the Marquess of Queensbury rules in a barroom brawl. It is to mistake the fundamental nature of the discourse and to assess it by criteria it was never meant to meet. Perhaps in some contexts these utterances take on an even more sinister aspect. Maybe saying “Mexican immigrants are rapists!” is actually a speech-act, a way of making a threat or intimidating.

Irrational people are often much cleverer than rational people. Rational people, bound by a principled devotion to truth, will generally respond to a post-truth narrative as if it were merely a set of falsehoods, which it is their job to correct. For instance, to the claim that immigrants are criminals, they will cite abundantly-documented, authoritative studies that show that first-generation immigrants, whether they entered legally or illegally, have lower rates of crime than the general population. True, but utterly irrelevant to the purposes of the rabble-rousing demagogue, who does not care at all if the claim is true or false, but only that it has the desired effect. While rational people struggle, entangled in the net of falsehoods like Laocoön in the coils of the serpents, the demagogue laughs at them in his rearview mirror as he speeds on to his next rhetorical triumph. “Suckers!” he gloats, sneering at the ineffectual writhing of his would-be debunkers.

So, what is a rational person to do when confronted with the purveyors of post-truth narratives? DO NOT try to engage them in rational debate. Hillary Clinton tried that—three times. When he went low, she went high. Then he went lower. For post-truthers, a debate is anything but a venue for logical argument and the presentation of evidence. Don’t think Oxford Debating Union. Think holy-roller tent revival. The point is to yank in the yokels and bring ‘em to Jesus.

How can you make post-truthers respect the truth? You can’t. Can you embarrass them with facts? No way. What you can do is to fight words with actions. I saw comedian John Oliver’s show yesterday, and he had it right. Don’t gripe, whine, or wallow in self-pity. Get busy. Contribute to groups that stand for what you stand for. For instance, don’t waste your breath on climate-change denialists, like that ignorant jackass Myron Ebell that Trump put in charge of the transition at the EPA. Instead, contribute to the environmental or conservation group of your choice. I just did. Or contribute to an organization that defends reproductive rights, or the rights of immigrants, or to an organization that supports science over claptrap. Get involved with groups in your community. Fight irrational words with rational actions.