"The progressive mindset is screwing up the world. The progressive mindset is guaranteeing no progress on global warming. The progressive mindset is saying, 'Yes, fracking is fine.' The progressive mindset is saying, 'Yes, genetically modified organisms are OK', when, in fact, they're horrible, and the progressive mindset doesn't know how to describe how horrible they are. There's a difference between progressive morality, which is great, and the progressive mindset, which is half OK and half awful."

George Lakoff, professor of cognitive science at the University of California, Berkeley, has been working on moral frames for 50 years. In Communicating Our American Values and Vision, he gives this precis: "Framing is not primarily about politics or political messaging or communication. It is far more fundamental than that: frames are the mental structures that allow human beings to understand reality – and sometimes to create what we take to be reality. But frames do have an enormous bearing on politics … they structure our ideas and concepts, they shape the way we reason … For the most part, our use of frames is unconscious and automatic."

Lakoff is affable and generous. In public meetings he greets every question with: "That is an extremely good question." But he cannot keep the frustration out of his voice: the left, he argues, is losing the political argument – every year, it cedes more ground to the right, under the mistaken impression that this will bring everything closer to the centre. In fact, there is no centre: the more progressives capitulate, the more boldly the conservatives express their vision, and the further to the right the mainstream moves. The reason is that conservatives speak from an authentic moral position, and appeal to voters' values. Liberals try to argue against them using evidence; they are embarrassed by emotionality. They think that if you can just demonstrate to voters how their self-interest is served by a socially egalitarian position, that will work, and everyone will vote for them and the debate will be over. In fact, Lakoff asserts, voters don't vote for bald self-interest; self-interest fails to ignite, it inspires nothing – progressives, of all people, ought to understand this.

When he talks about the collapse of the left, he clearly doesn't mean that those parties have disintegrated: they could be in government, as the Democrats are in the US. But their vision of progressive politics is compromised and weak. So in the UK there have been racist "Go home" vans and there is an immigration bill going through parliament, unopposed, that mandates doctors, the DVLA, banks and landlords to interrogate the immigration status of us all; Hungary has vigilante groups attacking Roma, and its government recently tried to criminalise homelessness; the leaders of the Golden Dawn in Greece have only just been arrested, having been flirting with fascism since the collapse of the eurozone. We see, time and again, people in need being dehumanised, in a way that seems like a throwback to 60 or 70 years ago. Nobody could say the left was winning.

Lakoff predicted all this in Moral Politics, first published in 1996. In it, he warned that "if liberals do not concern themselves very seriously and very quickly with the unity of their own philosophy and with morality and the family, they will not merely continue to lose elections but will as well bear responsibility for the success of conservatives in turning back the clock of progress in America." Since then, the left has cleaved moderately well to established principles around the politics of the individual – women are equal, racism is wrong, homophobia is wrong. But everything else: a fair day's work for a fair day's pay, the essential dignity of all humans, even if they're foreign people or young people, education as a public good, the natural world as a treasure rather than an instrument of our convenience, the existence of motives besides profit, the pointlessness and poison of privatisation, the profundity, worth and purpose of pooling resources … this stuff is an embarrassment to centre-left parties, even when they're in government, let alone when they're in opposition. When unions reference these ideas, they are dismissed as dinosaurs.

Yet equivalent rightwing positions – that efficiency is all, that big government is inefficient and therefore inherently bad, that nothing must come between a business and its pursuit of profit, that poverty is a lifestyle choice of the weak, that social breakdown can be ascribed to single mothers and immigrants – have been subject to no abatement, no modification, no "modernising".

If we accept Lakoff's conclusion, what would it mean to accept his prescription? This is what he believes it would take to refashion the progressive mindset: the abandonment of argument by evidence in favour of argument by moral cause; the unswerving and unembarrassed articulation of what those morals are; the acceptance that there is no "middle" or third way, no such thing as a moderate (people can hold divergent views, conservative on some things, progressive on others – but they are not moderates, they are "biconceptual"); and the understanding that conservatives are not evil, unintelligent, cynical or grasping. Rather, they act according to the moral case as they see it. If they happen to get rich, and make their friends rich in the process, that is just the unbidden consequence of wealth being the natural reward of the righteous, in their moral universe. To accept, let alone undertake, any of this, one would first need to accept the veracity of frames.

Much of cognitive linguistics concerns itself with how we build the mental apparatus to understand everyday situations: a hospital, or a date, or a cash machine. Erving Goffman, commonly cited as the most influential sociologist of the 20th century, wrote Frame Analysis in 1974, defining and exploring exactly how this happens. Having built the frames to understand life, we no longer deliberately plug back into it. It is unconscious; what we think of as "common sense" is merely an act or notion that resonates with one of our deep frames.

Lakoff's work on the conceptual systems around morals and politics (and how they show up in language) has yielded two-dozen metaphors for morality, most of them universal across cultures. Of those, the two key frames informing political judgment involve the idea of government as a family: the strict-father model (conservative) versus the nurturant-parent model (progressive).

I talk to Lakoff when he is invited over to London by Counterpoint, a thinktank with an interest in how ideas can be used to quell the xenophobia and repression that has, of late, swept Europe. In the strict-father worldview, he explains, "The father is the ultimate authority, he knows right from wrong, his job is to protect the family and so he's the strongest person, and because he knows right from wrong, his authority is deserved. His children are born bad, because they just do what feels good, they don't do what's right. They have to be trained out of feelgood liberalism into doing what's right. You have to punish the kids painfully enough that they'll start doing what's right and they'll get discipline. If they're disciplined, they go out into the world, and they earn a living. If they're not earning a living, they're not disciplined, therefore they can't be moral and they deserve their poverty."

To liberals, a lot of conservative thinking seems like a failure of logic: why would a conservative be against equal rights for women and yet despise the poor, when to liberate women into the world of work would create more wealth, meaning less poverty? And yet we instinctively understand those as features of the conservative worldview, and rightly so.

The nurturant-family model is the progressive view: in it, the ideals are empathy, interdependence, co-operation, communication, authority that is legitimate and proves its legitimacy with its openness to interrogation. "The world that the nurturant parent seeks to create has exactly the opposite properties," Lakoff writes in Moral Politics. As progressives identify failures of logic in the conservative position, so it works the other way round (one of Lakoff's examples: "How can liberals support federal funding for Aids research and treatment, while promoting the spread of Aids by sanctioning sexual behaviour that leads to Aids?").

I am accustomed to seeing our current situation as a feature of the past 30 years; a post-ideological landscape, in which the great left-right clashes of the 80s gave way to Blair (and Clinton's) third way on one side, and the unemotional, rational free market on the other. In fact, Blair conceded ground on the left, but the right didn't concede any; as things are, free-market rules evaluate human importance based on wealth, and as such are plainly ideological, in a strict-father frame.

Whatever the calamities of the last three decades, however, these two value systems – strict father versus nurturant family – have been clashing for ever. Lakoff says: "After I published Don't Think of an Elephant! [probably his most celebrated book], a British historian read it and said, 'In studying the civil war in the 17th century, I see the same thing.' But this is more than centuries old. This goes back to the Bible. You have two views of God: you have the strict father God and the nurturing God. You have Christ the warrior and Christ the saviour."

If the two systems are poised in pure opposition, if they are each as moral, as metaphorical, as anciently rooted, as solidly grounded as the other, then why is one winning? "Progressives want to follow the polls … Conservatives don't follow the polls; they want to change them. Political ground is gained not when you successfully inhabit the middle ground, but when you successfully impose your framing as the 'common-sense' position."

If all political belief originates from one of two wellsprings, if the last thing you should do to propagate your belief is to water it down, if backing it up with facts just weakens it, what would a debate look like, in a world of perfectly understood frames? Say your opposer was Todd Akin, the Republican who notoriously opposed abortion even for rape victims, on the basis that proper victims didn't normally get pregnant because "the female body has ways to try to shut that whole thing down". It is an extreme example, but justifiable, I think: to try to argue against that with a moral case, rather than basic biological realities, would be missing a trick. Lakoff shakes his head: I can see him thinking, "Forget tricks!" Instead, he says: "You have to go up a level, to the moral level. You have to say, this is somebody who's interested in male domination. That's what liberals are afraid to do."

A classic liberal pitfall is the idea that by repeating one of the opposition's ridiculous lines, you make it look even more absurd. "There was an election in Wisconsin," Lakoff says, "there was a horrible governor there, and the Democrats were so stupid that they put up billboards all over the state with a picture of him smiling. They had his name in large letters next to the picture, and it says, 'Why is this man smiling?' And then in smaller type, it has a list of his positions, all from his point of view? As if everybody will recognise that this is a horrible man. Instead, it is a billboard in his favour. It's about time progressives got out there and said what's true about themselves, as well as what's true of the other side. If you have a strong position, let's hear it."

One of Lakoff's engagements in London was at the TUC, where they proudly showed him a video they had made about welfare, and it fell into all these Wisconsin pitfalls – restating Cameron's case in order to dispute it, but in reality falling into the trap of trying to dispel welfare "myths", instead of talking about a social security system of which we should be proud. He took it apart at the seams.

You want to defend the right to have an abortion, you want to stop privatisation, you want to protect the natural world – as Lakoff has often written, these are not three separate arguments, they are all part of the same worldview. But that isn't to say that he considers them equally important, and the urgency of his speech ramps up as he talks about monetising nature. "What we get from nature is remarkable. And then you get the people who want to monetise that. If it's valuable, what's the value? What's it worth? Which is the wrong question to ask, because, first of all, much of its value has to do with what is visceral to you. What does it mean to you if you hear the birds singing, or the birds all die? Second, as soon as you monetise something in nature, a cost-benefit analysis will come in. Nature always loses, because nature goes on for ever."

It is, plainly, the longstanding failure to protect nature that powers Lakoff's exasperation with liberals. "They don't understand their own moral system or the other guy's, they don't know what's at stake, they don't know about framing, they don't know about metaphors, they don't understand the extent to which emotion is rational, they don't understand how vital emotion is, they try to hide their emotion. They do everything wrong because they're miseducated. And they're proud of that miseducation. Oxford philosophy reigns supreme, right? Oxford philosophy is killing the world."