A Fraction of the Whole, By Steve Toltz

It's no surprise that the Australian author of A Fraction of the Whole, at 36, is a little older than we've come to expect from our debut novelists. This absurdly incident-laden, feverish, farcical 700-page life story bears the watermark of long gestation. What's more, it stands above the vast majority of debut novels because it seems so marvellously sure of itself and what it should be.

That's a paradox, given that an identity crisis – that of narrator Jasper Dean – is at its heart. We first encounter Jasper in an Australian prison; he wants to explain how, or, more precisely, why he got there. So begins an outpouring that sees Jasper ruminate on the relationship that has unmade him: that with his late father, Martin, a restless, paranoid, anti-social wannabe philosopher who died hated by his countrymen.

There is no single plot in this episodic novel. So profuse is Jasper's narrative that it seems gloriously in danger of eating itself. We start with Martin Dean's small town childhood, during which he nurses feelings of superiority and sees his brother Terry begin a career as an outlaw. When Terry dies in a vast fire – it starts at an observatory built at Martin's suggestion – Martin travels to Paris, and becomes involved in an Arab underworld sting that causes the death of Jasper's mother. Soon, father and son are back in Australia, hiding in a labyrinth they built themselves.

Upon this picturesque background Toltz hangs Martin and Jasper's cacophonous, endless theorising on politics, sport, childhood, the media and musical chairs. On health: "The difference between rich and poor is nothing. It's the chasm between the healthy and the sick you just can't breach." On democracy: "There's never been a great democratic country because there has never been a great bunch of people." But Toltz's fizzing, acid, funny prose is also capable of a kind of broken, lyrical beauty. "Her mask was a weave of tattered shreds torn from all the beautiful parts of herself," we learn about the woman Martin loves, Caroline.

Toltz heaps narrative twist upon incredible twist. When Martin's latest dodgy scheme fails – he wanted to make every Australian a millionaire – he and Jasper flee to Thailand. Here, a secret casts a new light on the last four decades. It's here, too, that Toltz's true narrative thread is allowed, at last, to move us. In less skilled hands, Fraction could be a sterile work; one of those fashionably sprawling novels that generate far more heat than light. But amid the dizzying whirl of events, Toltz never loses sight of a deep current that runs throughout his story: Jasper's longing to know himself. Constantly he asks: what makes a man who he is? His ideas? Fate? His decisions? His father?

It's a spiritual search that allows lines as beautiful as: "The rhythms of the universe were perceptible in the way the boats were nodding at me," and allows a conclusion that finds an affecting depth of feeling. Yes, A Fraction of the Whole is a wildly looping rollercoaster. But there's much more to it than meaningless exhilaration.