Book of a lifetime: On the High Wire by Philippe Petit In 1985 I worked for the Strand, New York's most famous second-hand bookstore. One April morning I was arranging new stock on the trestle tables in Bryant Park when my hand snagged on a book that was almost square. Its cover was white, with a black line across it. A man lay on his back on the line, his left arm and leg dangling, his face in stark silhouette, puckish and ecstatic. The line was a tightrope. The man was Philippe Petit, the French high-wire artist who walked between the Twin Towers illegally in 1974. On the back I found a quote by Werner Herzog: "This is a book of instructions to those who will one day dare the impossible." In his introduction to On the High Wire, Marcel Marceau describes Petit as being "someone who seems to have escaped from another planet," and Petit's other-worldliness is immediately apparent if you read about his life. For years, his only residence was a broom cupboard in Paris. Not a room exactly. More of a corridor. His writing, translated by Paul Auster, is equally spare and strange. Even his chapter titles are evocative: Barefoot, The Wind, Perfection, Fear. He is most compelling when he talks about the specifics of his craft. He describes how to clean a steel cable by washing it in gasoline, then rubbing it with emery. When he practises, he often rigs up a wire outdoors, between two trees - "preferably, trees with character." He likes to make things difficult for himself, wire-walking after drinking, or in unmatching shoes, or during a gale. Years of practice have left a mark on the soles of his feet - what a friend of his calls "the line of laughter." His subjects are concentration, humility, and becoming one with his surroundings. When you see pictures of Petit walking between the towers of Laon Cathedral in 1974, you understand why a journalist once accused him of having a death-wish. At the same time, you understand Petit's response: "No, what I have is a life-wish." Punctuated by astounding photographs and illustrations, Petit meditates on his calling, his prose aphoristic, gem-like. The book is about what he does, but it's also about what we all do, if there's anything we're obsessed with, or passionate about. He outlines a whole approach to life, and his vision is pure, primitive and poetic; he leaves no room for cynicism. What counts is this," he says. To stay straight and stubborn in your madness. Only then will you defeat the secrets of the wire. The lessons are simple, universal. Be committed. Feel alive. Give everything. Rupert Thomson's new novel is "Secrecy" (Granta)