In the same way that truthiness has become central to our political discourse, there has also been a significant rise in the amount of bullshit. Lying for political advantage, of course, is as old as the hills. What has changed is that politicians used to worry about getting caught. Lying also requires some effort " you have to come up with something that, if not exactly true, at least sounds true. But there came a point when politicians discovered that if you simply kept repeating the same thing over and over again, a lot of people would come to believe it regardless of whether it was true or not. And in a democracy, what the majority believes is much more important than what is actually the case. As a result, many politicians dropped even the pretense of trying to tell the truth.

There are many examples of this new attitude on display, but one of the most striking occurred in the fall of 2012, when the Conservative government in Canada decided to accuse the opposition New Democratic Party of supporting a carbon tax. Anyone who had been paying attention knew this to be not only false, but the opposite of true. The NDP probably should support a carbon tax, given its left-wing, environmental sympathies. And yet one of the more controversial aspects of its platform has been its vocal opposition to carbon taxes. During the 2008 federal election, when the Liberal Party of Canada actually ran on a carbon tax platform, the NDP upset an enormous number of environmentalists by opposing it. And in British Columbia, the only jurisdiction in Canada that has actually implemented a carbon tax to date, the NDP has consistently threatened to repeal it if elected. (The federal NDP’s official policy is in support of a cap-and-trade system, the same policy that the Conservatives supported and campaigned on during the previous two elections.)

If the Conservative accusation had simply been put forward as an argument, then of course it would have been quickly dismissed. What the Conservatives decided to do instead was to have every member of Parliament on their side use the phrase ”œcarbon tax” (or better yet, ”œjob-killing carbon tax”) on almost every occasion that anyone rose to speak, regardless of the topic, and claim that the NDP supported it. This went on literally for weeks, to the point where one journalist described it as the ”œdeath by talking point” strategy.  In a breach of parliamentary tradition, not to mention decorum, they also had their backbenchers recite the same talking points during their members’ statements " made during a fifteen-minute period before the beginning of Question Period, when members are entitled to rise to make a statement to the House of their choosing (traditionally used for tributes to deceased constituents or to announce events in their ridings).

The Canadian print media, not being quite as supine as their American counterparts, immediately denounced the carbon tax claim as a ”œlie” and roundly condemned the tactic for its political cynicism.  Yet this did not deter the Conservative government from following up with a nationwide radio and television advertising campaign repeating the same false claim about NDP support for carbon taxes.

The accusation was bullshit, in the technical sense of the term. Relentless bullshit, however, creates something of a dilemma for those being subjected to it. In a sense, all that the NDP could do was deny that it supported a carbon tax. But it’s very difficult to do this without yourself using the phrase ”œcarbon tax.” So what the average person hears is simply ”œcarbon tax, NDP, carbon tax, NDP, carbon tax, NDP, carbon tax…” And that’s precisely the point. Pretty soon ”œlow information” voters were probably saying to themselves, ”œThe NDP, aren’t those the guys who support a carbon tax?” That was, in any case, the Conservative ambition. It was a classic instance of what is now routinely called a ”œpost-truth” political strategy.

This privileging of visceral, intuitive, gut feelings is central to the movement known as ”œcommon sense” conservatism, which has become a powerful force everywhere in the Western world, not just the United States.

Some people like to find ”œbalance” whenever discussing politics, to see the left and the right as mirror images of one another. When it comes to attitudes toward truth, however, there are clear differences. Democratic Party politicians in the United States may manipulate, exaggerate, and lie, but they are not unhinged from reality. When they debate policy, they still make some attempt to discuss the actual issues. The debates between Barack Obama and Hillary Clinton on the subject of health care during the Democratic primaries in 2008, for instance, provided a fairly reliable sense of what each candidate actually intended to do with that file. At no point did it degenerate into the sort of display that has become commonplace among Republicans, with each contender competing against the others to say how many government departments he would close down upon being elected " when no one could believe for an instant that any of them would do any such thing.

The difference is that conservatives have become enamored of the idea that politics is ultimately not about plans and policies, it’s about ”œgut feelings” and ”œvalues.” Elections are decided by appealing to people’s hearts, not their heads. So, for example, when a Republican candidate says that he is going to ”œclose down the Department of Energy,” he doesn’t really mean that he is going to close down the Department of Energy and fire all of its employees. After all, the U.S. Department of Energy is responsible for maintaining the nuclear reactors in U.S. military submarines, among other things. What it really means to say that you’ll close down the Department of Energy is just ”œI feel very strongly that the federal government hates oil companies, and I want to change that.” The objective is to communicate your feelings, not your thoughts.

This privileging of visceral, intuitive, gut feelings is central to the movement known as ”œcommon sense” conservatism, which has become a powerful force everywhere in the Western world, not just the United States. The central characteristic of common sense, according to Republican communication strategist Frank Luntz, is that it ”œdoesn’t require any fancy theories; it is self-evidently correct.” To say that it is self-evident is to say that it is known to be correct without argument and without explanation. Thus, making common sense the core of one’s political ideology amounts to a pure privileging of intuition over rational thought, of ”œgut feeling” over deliberation, and of heart over head. Indeed, one can see in Luntz’s description the explicit downgrading of rationality. Common sense is independent not just of ”œtheories,” but of ”œfancy theories”" the kind proposed by effete East Coast intellectuals. The crucial thing about fancy theories is that you can feel free to ignore them, precisely because they are fancy. You don’t have to worry about the actual content of what the person is saying.

Joseph Heath is an associate professor in the Department of Philosophy at the University of Toronto. Excerpted from Enlightenment 2.0, by Joseph Heath © 2014. Published by HarperCollins Publishers Ltd. All rights reserved. Used by permission.