I have an aversion to what I see as needless acts of bravado. People who sail single-handed round the world or scale the north face of the Eiger without crampons interest me little. Life, everyday mundane life, is quite risky enough without adding gratuitous danger.

For those reasons I had avoided seeing the film Man on Wire when it first came out in cinemas. This is the documentary, you may recall, about the French funambulist Philippe Petit, who walked on a wire between the Twin Towers of the World Trade Center in 1974, briefly becoming an international celebrity.

But when I finally caught up with Man on Wire on terrestrial TV, I found myself more gripped than I had expected. It was not just that I had underestimated the sheer outré daring of the act itself, but I had not considered the logistics, and teamwork, that made it possible.

Of course, if you think about it, getting a ton of rigging to the top of one of the towers and somehow stringing and securing a cable across (using a bow and arrow, attached to a fine thread, attached to a bigger thread and so on) was as remarkable and unlikely an achievement as the high-wire walk itself – probably much more so.

You might think of Petit as a nut, on a par with Timothy Treadwell, the hero of Herzog’s Grizzly Man, who believed he could fraternise with bears, but, if so, he was an inspired and inspiring nut. He had enough charisma (and for once I think that is the mot juste) to persuade a whole team of camp followers to go along with him.

This was the true essence of the film, how Petit persuaded friends, colleagues, girlfriend to make his crazy dream come true. What did they think they were doing? How would they have felt if he had plunged 1,300ft to his death?

The film persuaded you that they were not foolish or deluded. The footage of Petit practising walking on a tightrope, both before the 1974 feat and 30-odd years later, showed something unmistakable and mesmerising. This was a man born to walk on a high wire. The expression on his face in mid-walk, rightly described by one of his friends as a mask of concentration, was both transfixing and strangely archaic, like the expression of a Minoan bull-leaper. And when Petit finally performed his famous feat, photographs clearly show his face relaxing from tension into serenity.

Petit did not just walk once and for all along the wire between the towers. As one of the policemen sent to catch him put it: “He danced on that wire,” lying on it, kneeling on it, returning to make the crossing eight times. In the film, his friends repeatedly bear witness to the strange and captivating beauty of the act.

Petit’s high-wire walk was a kind of triumph, but not without human cost. All his friends agreed that something changed after it. Petit had survived unscathed, and even been transformed into a kind of demigod, but his terrestrial relationships did not fare so well. His relationship with his girlfriend died more or less in the act; just after it, Petit was invited by a star-struck admirer to go to bed with her and accepted.

He himself was, and remains to this day, unrepentant. Being French, he sees his high-wire act as a philosophical statement as much as a physical one. His feat was the most extreme rebuke imaginable to a culture obsessed with safety at all costs. For Petit, life is only really lived at the extreme, which does not mean with pointless recklessness but in a fully conscious wager with death. Only that way can a terrible beauty be born.

Most of us choose not to live on the high wire, either literally or metaphorically. From childhood we are warned against the perils of flying too high – not just our individual childhood, but the childhood of the race, when the Greek myth of Icarus taught the danger of flying too close to the sun.

But Philippe Petit and all the people who supported him – his rigging team, the employee in the World Trade Center who helped him forge a pass, even the amazed policeman touched with eloquence by what he saw – were convinced of something different. Sometimes the supreme expression of life is something that defies all the rules of caution.

This applies beyond funambulism. The other night at the BBC Proms I found myself feeling strangely out of sorts. An atmospheric but shapeless contemporary piece by John Casken did little to change my mood.

But then the pianist Stephen Hough came on to play Tchaikovsky’s Second Piano Concerto, whose main raison d’être seems to be to challenge the pianist to play more notes and at greater velocity than is humanly possible. But, improbably, Hough pulled it off, playing not just fast but with refined delicacy and in the romping finale with delicious insouciance. Here was a high-wire act of another kind, uplifting to the spirit.

harry.eyres@ft.com
More columns at www.ft.com/eyres