IN 1962 a British political scientist, Bernard Crick, published “In Defence of Politics”. He argued that the art of political horse-trading, far from being shabby, lets people of different beliefs live together in a peaceful, thriving society. In a liberal democracy, nobody gets exactly what he wants, but everyone broadly has the freedom to lead the life he chooses. However, without decent information, civility and conciliation, societies resolve their differences by resorting to coercion.

How Crick would have been dismayed by the falsehood and partisanship on display in this week’s Senate committee hearings in Washington. Not long ago social media held out the promise of a more enlightened politics, as accurate information and effortless communication helped good people drive out corruption, bigotry and lies. Yet Facebook acknowledged that before and after last year’s American election, between January 2015 and August this year, 146m users may have seen Russian misinformation on its platform. Google’s YouTube admitted to 1,108 Russian-linked videos and Twitter to 36,746 accounts. Far from bringing enlightenment, social media have been spreading poison.

Russia’s trouble-making is only the start. From South Africa to Spain, politics is getting uglier. Part of the reason is that, by spreading untruth and outrage, corroding voters’ judgment and aggravating partisanship, social media erode the conditions for the horse-trading that Crick thought fosters liberty.

A shorter attention spa...oh, look at that!

The use of social media does not cause division so much as amplify it. The financial crisis of 2007-08 stoked popular anger at a wealthy elite that had left everyone else behind. The culture wars have split voters by identity rather than class. Nor are social media alone in their power to polarise—just look at cable TV and talk radio. But, whereas Fox News is familiar, social-media platforms are new and still poorly understood. And, because of how they work, they wield extraordinary influence.

They make their money by putting photos, personal posts, news stories and ads in front of you. Because they can measure how you react, they know just how to get under your skin (see article). They collect data about you in order to have algorithms to determine what will catch your eye, in an “attention economy” that keeps users scrolling, clicking and sharing—again and again and again. Anyone setting out to shape opinion can produce dozens of ads, analyse them and see which is hardest to resist. The result is compelling: one study found that users in rich countries touch their phones 2,600 times a day.

It would be wonderful if such a system helped wisdom and truth rise to the surface. But, whatever Keats said, truth is not beauty so much as it is hard work—especially when you disagree with it. Everyone who has scrolled through Facebook knows how, instead of imparting wisdom, the system dishes out compulsive stuff that tends to reinforce people’s biases.

This aggravates the politics of contempt that took hold, in the United States at least, in the 1990s. Because different sides see different facts, they share no empirical basis for reaching a compromise. Because each side hears time and again that the other lot are good for nothing but lying, bad faith and slander, the system has even less room for empathy. Because people are sucked into a maelstrom of pettiness, scandal and outrage, they lose sight of what matters for the society they share.

This tends to discredit the compromises and subtleties of liberal democracy, and to boost the politicians who feed off conspiracy and nativism. Consider the probes into Russia’s election hack by Congress and the special prosecutor, Robert Mueller, who has just issued his first indictments. After Russia attacked America, Americans ended up attacking each other (see article). Because the framers of the constitution wanted to hold back tyrants and mobs, social media aggravate Washington gridlock. In Hungary and Poland, without such constraints, they help sustain an illiberal, winner-takes-all style of democracy. In Myanmar, where Facebook is the main source of news for many, it has deepened the hatred of the Rohingya, victims of ethnic cleansing.

Social media, social responsibility

What is to be done? People will adapt, as they always do. A survey this week found that only 37% of Americans trust what they get from social media, half the share that trust printed newspapers and magazines. Yet in the time it takes to adapt, bad governments with bad politics could do a lot of harm.

Society has created devices, such as libel, and ownership laws, to rein in old media. Some are calling for social-media companies, like publishers, to be similarly accountable for what appears on their platforms; to be more transparent; and to be treated as monopolies that need breaking up. All these ideas have merit, but they come with trade-offs. When Facebook farms out items to independent outfits for fact-checking, the evidence that it moderates behaviour is mixed. Moreover, politics is not like other kinds of speech; it is dangerous to ask a handful of big firms to deem what is healthy for society. Congress wants transparency about who pays for political ads, but a lot of malign influence comes through people carelessly sharing barely credible news posts. Breaking up social-media giants might make sense in antitrust terms, but it would not help with political speech—indeed, by multiplying the number of platforms, it could make the industry harder to manage.

There are other remedies. The social-media companies should adjust their sites to make clearer if a post comes from a friend or a trusted source. They could accompany the sharing of posts with reminders of the harm from misinformation. Bots are often used to amplify political messages. Twitter could disallow the worst—or mark them as such. Most powerfully, they could adapt their algorithms to put clickbait lower down the feed. Because these changes cut against a business-model designed to monopolise attention, they may well have to be imposed by law or by a regulator.

Social media are being abused. But, with a will, society can harness them and revive that early dream of enlightenment. The stakes for liberal democracy could hardly be higher.