Liberals and left-wing types are usually well-educated, yet, time and again, they show extraordinary ignorance about what motivates people to take one political stance over another.

The idea that voters calmly and unemotionally weigh up the pros and cons of Remain versus Leave, for example, or Clinton versus Trump, is a fantasy.

As the Scottish Enlightenment thinker David Hume wrote: “Reason is, and ought only to be, the slave of the passions, and can never pretend to any other office than to serve and obey them.”

A hundred years of cognitive science has shown this to be the case: humans are intuitive creatures. Emotions come first, justifications for a decision or action come later.

It might be a welcome thing if we were all unflappable, reasoning machines, but if the political left is banking on this to achieve its goals, it will have to wait effectively until society is run by artificial intelligence.

So what should the left do? As someone who always self-identified in that camp, I humbly suggest three things:

1. Start talking about values rather than evidenced-based policy

Politicians who think of themselves as progressive like to ask experts or “independent” consultants what should be done.

But no one is without ideological bias and eventually you have to stand up for what you believe in.

One of the reasons why the Leave campaign did so well in the UK is because it addressed fundamental values: it spoke to people’s core beliefs in freedom and self-determination.

The Remain side responded with economic and diplomatic arguments when it should have concentrated on values too, for example, celebrating the virtues of compassion, charity, humility and justice (in an international sense).

Conservatives are more comfortable talking about morality, whereas liberals tend to regard it as a private matter. They need to get over this, and fast.

Twenty years ago, the cognitive scientist George Lakoff wrote in his book Moral Politics: “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.”

The warning is even more stark today.

2. Quit demonising free enterprise

Any form of socialism that prohibits free enterprise is neither desirable nor feasible in a democratic society. Wherever such socialism has been trialled it has been a disaster, and no electorate that is free from state control would vote for it.

The only form of socialism capable of gaining significant public support is “market socialism”.

As articulated by Axel Honneth and other left-leaning political theorists, this would acknowledge the role of individual choice in facilitating human flourishing, but would also seek to regulate markets to avoid gross injustice.

At a fundamental level, freedom and equality should be presented as allies not enemies.

The left has a simple but potentially effective message for its political opponents here: Your freedom is enhanced by other people’s freedom.

3. Build bridges with people of faith

In the past century, some of the most progressive causes – promoting civil rights, international solidarity, environmental responsibility and nuclear disarmament – have been led, or heavily influenced, by people of a religious background.

In the US, Christian activists like Martin Luther King and the Berrigan brothers have had a profound influence on the American conscience. In Ireland today, probably the most credible social commentator of the left is Fr Peter McVerry.

Yet, liberals, lefties, progressives (call us what you will) typically have a problem engaging with religion.

The (liberal) legal scholar and secular humanist Ronald Dworkin addressed this issue in the last book he wrote before his death, Religion Without God. In it, he suggests that people of all faiths and none can find common ground by adopting a “religious attitude” which, he says, accepts the truth of two central judgements:

“The first holds that human life has objective meaning or importance . . . The second holds that what we call ‘nature’ – the universe as a whole and in all its parts – is not just a matter of fact but is itself sublime: something of intrinsic value and wonder.”

Whether you call this religious or not, the attitude described by Dworkin is precisely what’s needed to make progress on social affairs.

For those of us who are on the left (or at least firmly not on the right) in today’s fractured Europe, we need to start believing again.