Just after dawn on August 7, 1974, on a hazy summer's morning, Philippe Petit stood on the edge of the south tower of Manhattan's World Trade Centre. The daredevil Frenchman didn't look down as he stepped off the 110-storey building and slowly walked 43m between the two towers. And did so again. And another six times. There was no harness nor safety net, just a slender steel cable separating him from death.
Petit, whose daring feat was highlighted in the 2008 documentary Man on Wire, and who has since gone on to complete death-defying strolls across the Grand Canyon and the Seine river, admits he often did so in the shadow of fear.
"I always worried: was the cable too steep, had there been an error in rigging calculations," he said. "Fear invaded me and sucked my blood."
Thankfully, most of us will never be exposed to the level of fear that Petit was. Or have to bend it to our will. But that doesn't stop us from being more afraid than we possibly ever have. Research shows that our global laundry list of fears includes, but isn't limited to, terrorism, road rage, unemployment, migration, flesh-eating bacteria, right-wing populism, environmental apocalypse and financial collapse.
Ironically, sociologists say contemporary Western societies experience much less pain, suffering, debilitating disease and death than they did in the past (compared to the developing world). What's more, we actually enjoy an unprecedented level of househould weath, longevity, education and personal safety.
So how is it possible to live in the safest time in human history, yet at the same time to be so fearful? Heinz Bude reckons he knows the answer.
"Our age is characterised by fear because of changes in our environment, such as the rise of terrorism and floods of migrants, as well as the uncertainties associated with economic crisis and recession," says the German sociologist, who recently released his 10th book, Society of Fear.
"Unlike post-World War II, when society clearly understood that things could only get better, in the 21st century there's a sense of being thrown into a world where we no longer belong. We are uncertain about the future, about what's going to happen, and this unsettling uncertainty, suppressed anger and unexpressed bitterness is what makes us one of the most fearful societies ever."
Bude is speaking to me from his office at the University of Kassel, two-and-a-bit hours from his home in Berlin. He might be one of Germany's leading sociologists, with an impressive string of letters after his name, but the 63-year-old isn't terribly flash when it comes to Skype, being unable to operate his camera or keep his microphone from fading in and out of the conversation.
But then Bude has more important things on his mind. Such as Western society's 50 shades of fear.
"While we may disagree on almost everything else, what we can agree on is that we are all afraid. Fear transcends social classes and generations, and it is infinite — there is always something new to fear."
In lightly accented English, Bude explains that the seemingly endless range of possibilities that most of us enjoy today is a key factor in our culture of fear.
"You go into the supermarket and there are 40 types of cheese. Or you have a range of schools in which to place your child, or lots of places to go on holiday. Choice seems to give us greater autonomy and freedom but every choice should have a meaning. In reality, the unknown impact and meaning of each option creates a vaccum, which is filled by fear."
Bude spends a lot of time thinking about fear. He wonders why we fear what we do, how long it will last and what we can do about it. His latest book, which he spent two years researching, breaks down the many ways in which fear chokes us, from relationships and social media ("we constantly compare ourselves with others and fear being left out or left behind"), to the repressed anger of the lower classes ("they want a place in the sun like everyone else but instead are passed over, embarrassed, rejected").
It's equally grim for the middle classes: fear, he believes, has its muddy boot on the middle class windpipe and continues to press down.
"Fear afflicts those who have something to lose, who feel insecure in their position on the social ladder," he says.
It's what Bude refers to as "status panic" — middle class jobs are becoming scarcer and/or shifting to contract or freelance work, earnings aren't rising and status is becoming precarious.
"The middle classes are the ones who pay most of the taxes and the entire social system is ultimately geared towards their way of life. But suddenly they see their status under threat. No one knows how long the kind of life guaranteed by a comfortable income and elevated esteem can be sustained, which is why the middle layer of Western society seems to be unravelling."
The news doesn't get much better the further you dig into Bude's anlaysis: the middle classes also fear fitting in, of being found out as imposters or — quelle horreur — misinterpreting the unwritten social codes of the social groups they've infiltrated.
"Cosmopolitanism, ease and self-confidence are not so easy to learn and, for the social climber, the feeling of inadequacy never disappears."
In a chapter with the Abba-esque title "When The Winners Take It All", Bude claims that because we increasingly live in a society where so many people are competing for so few top spots, effort alone is no guarantee of success. Ditto educational qualifications, experience or loyalty.
"You need to have the X factor — you have to be quick, shrewd and bold, to offer something extra that makes you appear cleverer, more dazzling and daring than the rest of the drab crowd. The 'winner takes it all' is a merciless concept and one that causes a lot of fear."
Despite the subject matter, Bude is cheerful and chatty; his long, looping sentences punched through with laughter. But 20 minutes into our interview, my spirits are flagging and I'm starting to feel depressed about the state of the planet. It might be time to change the subject.
Bude takes that as a cue to launch into the rise of populism. Society of Fear was published before Brexit and Trump tore a bloody great chasm in the planet's social fabric, so there's no mention of that in the book. But Bude has plenty to say about the forces that shaped it.
"This seething anger and overwhelming sense of powerlessness of so many makes the political use and abuse of fear possible. People like Trump offer a lifeline for those people's fears, the fear they have of migrants taking their jobs, of refugees they see as intruders, of helplessness.
"One side is afraid because it feels threatened by a minority and the other because it feels threatened by the majority."
He offers no easy fixes for our fears, saying there aren't any. "All we can do is accept fear as part of our lives. As President Roosevelt said, 'The only thing we have to fear is fear itself.'"
And be thankful that, unlike Petit, we don't have to confront our fears 110 storeys up.
Society of Fear by Heinz Bude (Polity, $41).