In the run-up to the presidential election Donald Trump apparently told the journalist Lesley Stahl that he very purposefully attacks the integrity of the press as a way of undermining what they write about him. “I do it to discredit you all and demean you all,” he’s alleged to have said. “So that when you write negative stories about me, no one will believe you.”

This won’t come as much of a revelation to anyone who’s watched Trump’s brand of politics over the last two years. His basic playbook, it seems, is to lie about something, to attack the press when they call him out on the lie, and then use the press’s criticism as evidence that what he’s saying must actually be true (they are, after all, ‘fake news’). There’s an inspired if deceitful logic to the whole thing. Although, when summarised in blunt terms like these, it seems amazing that it actually works as a strategy of persuasion. Yet here we are nearly a year and a half into his presidency and the tactic is still going strong – while the news media are still struggling to find ways to effectively deal with it.

The reason it works isn’t simply a matter of his relentlessly attacking the press however. It’s also to do with the way he manipulates the words and concepts he uses. It’s to do with the way he exploits the flexibility of language to create the specious logic which underpins his central narrative.

At the heart of this is a rhetorical technique which is particularly popular with people pushing conspiracy theories. This involves appropriating certain key words for purposes which appear to be the precise opposite of what these words conventionally mean. Take, for instance, the way that the conspiracy theorist website InfoWars uses the word ‘truth’. ‘Our team risks threats from the globalists and works hard every day to bring you the truth the Main Stream Media and Globalist forces don’t want you to hear’. Among the ‘truths’ they’ve been working so hard to promote is the idea that the Sandy Hook massacre, in which twenty young children were murdered, was entirely fabricated by the government. Then there’s the way that groups such as the 9/11 Truth Movement, who dispute the established account of the September 11th attacks, attempt to annex the same word. Or the way that the highly partisan Fox News used to use the slogan ‘fair and balanced’. In each case the organisations are resolutely using a term which runs counter received opinion about the way of the world, and in this way staking claim to that term for themselves.

Of course, language is always being manipulated for persuasive purposes. And as part of this, individual words often have their meaning stretched or twisted. From a purely technical point of view it would be wrong to categorise this as a ‘misuse’ of language, because it’s precisely this flexibility which makes it such a powerful means of communication.

From a moral perspective, on the other hand, this sort of manipulation can often be very questionable. At it’s most extreme it can lead to what’s known as doublespeak: language that purposefully distorts or obscures the straight-forward meaning of words so as to disguise the actual facts of the matter. This is something that’s particular prevalent in military discourse, which is rife with terms such as ‘enhanced interrogation’ (torture) and ‘ethnic cleansing’ (racially-motivated genocide). The National Council of Teachers of English in the US runs an annual Doublespeak Award for those who’ve ‘perpetuated language that is grossly deceptive, evasive, euphemistic, confusing, or self-centered’. Past winners include the U.S. State Department for their (aptly Orwellian) 1984 announcement that they’d ceased using the word ‘killing’ in official reports about overseas human rights abuses, and instead were using the phrase ‘unlawful or arbitrary deprivation of life’.

But the technique underpinning Trump’s game plan is rather different from this.  For most of the time he’s not simply trying to obscure events through the use of confusing or euphemistic language. Instead it’s what might technically be called ‘strategic catachresis’. Catachresis is a rhetorical term that refers to the use of a word or phrase in a way that significantly departs from its conventional usage. Or, as Dr Johnson put it, it’s when “words are too far wrested from their native signification”. So the word ‘truth’ when applied to hypotheses about elaborate government cover-ups, is being well and truly wrested from its native signification. In fact, it’s being strategically annexed by a group with a very different worldview from the mainstream. For those who believe in this worldview this isn’t doublespeak because it isn’t actually deceitful. Instead it’s an attempt to recalibrate the language.

Importantly, the reason this works is less to do with the word itself than with the wider narrative of which it’s a part. In cases such as these, ‘truth’ becomes less about observable facts, and instead refers to an extreme form of anti-establishment scepticism. And it’s precisely this narrative which Trump himself continues to talk up – and which allows him to upend the meaning of everyday words in the way that he does.