ow can I hope to convey to any reader my idea of Sydney?'' asks the novelist Peter Carey near the end of ''30 Days in Sydney,'' his ''wildly distorted'' account of a visit to the city he once called home. ''I have seen nothing to equal it in the way of landlocked scenery, in the particular relationship between the races, in the easy tolerance of crime and corruption, in the familiar mingling you can witness on the footpath outside Bar Coluzzi any morning, where you may find judges and writers and the euphemistically labeled 'colorful racing identities' all bunched happily together in the sunshine.''

In this passage, Carey echoes the words of an earlier Sydney chronicler, Anthony Trollope (''I despair of being able to convey to any reader my own idea of the beauty of Sydney Harbor''). But two more dissimilar perspectives can hardly be imagined. Whereas Trollope, in his 1873 travelogue ''Australia and New Zealand,'' was free to adopt the complacent attitude of an imperial tourist, Carey -- being Australian by birth, being modern, being Peter Carey -- is burdened with a more conflicted sensibility. His frank and restless book percolates with ambivalence, evincing a complicated attitude toward everything from the language used by Australian airline employees to the oddly genial attitude of Sydney's bike thieves. His view of this paradoxical city -- where the past is ''both celebrated and denied'' -- comes filtered through a tangled self-consciousness that his Victorian predecessor would have found entirely foreign.

Carey (the author, most recently, of the novels ''Jack Maggs'' and ''True History of the Kelly Gang'') also distinguishes himself from Trollope in having a greater repertory of narrative strategies at his disposal, and his book unfolds in many forms -- through arguments, dreams, anecdotes and tirades. Many of these originate with Carey's local friends, a lively, foulmouthed crew whose conversation is marked by a refreshing intolerance of cant and sentimentality. At first glance, they may strike readers as a familiar collection of erstwhile bohemians who now find themselves numbering, with one or two exceptions, among the dreaded middle-class elite. But while their American boomer equivalents have mostly said farewell to bongs and all-night debauches, these former hippies and dole bludgers don't seem to have let midlife respectability quash their taste for wild behavior.

Carey arrives in Sydney with a plan to collect from these friends their stories of ''Earth and Air and Fire and Water'' -- the natural elements that dominate this sea-washed, mountain-fringed city. And, with a little coaxing, his mates cooperate, feeding him tales of boating disasters in gale-force winds, raging wildfires and plunges into 2,000-foot canyons, all of which evoke the casual heroism and frontier-style self-sacrifice of the Common Bloke down under.

But as interesting as these stories are, they are delivered prefabricated, with well-meaning agendas attached. More revealing are the spontaneous arguments that flare up in the course of Carey's visit. ''Look, you're all so critical of everything,'' says one friend, now a high-placed government functionary, to a group of squatters bemoaning the commercial development of the city. ''You look down at Darling Harbor and say, oh, how awful. How unaesthetic. But you tell me . . . why are you living here? I'll tell you why. This is a fabulous view. It's a sensational place. . . . It's a city, mate, and it's exciting.''

Some of the book's most revealing arguments occur in Carey's own head. A few days into his trip, he internalizes the taunting narrative voice of the novel he's reading -- Flann O'Brien's ''Third Policeman'' -- and it proves a sly opponent in debating the more controversial elements of Australia's past. Were Sydney's aboriginal inhabitants, for instance, really pristine ''children of nature,'' as depicted in the romantic imagination of many Australians, or were they just as wasteful in their way as the Europeans who brutally displaced them? Was William Bligh, as governor of the convict colony, the absolute villain of traditional lore, or should he be given credit for having the courage to resist the entrenched forces of crime and cronyism? And what of the corrupt figure of John Macarthur, the Rum Rebellion leader who subsequently acted as Sydney's mob boss, dominating the commercial and political life of the city by controlling its rum supply? Carey and his demon have their disagreements on this score:

''Wait a minute,'' the voice objects. ''Is this the same Macarthur who is called the father of the Australian wool industry?''

''The very same man.''

''And is wool not the business that made the colony feasible? Should you not acknowledge him in some way? . . . Should you not have a monument to him at least?''

But ''30 Days in Sydney'' ranges too freely to linger on Socratic dialogues concerning the moral ambiguities of Australian history. Much of the book is overtly celebratory. And Carey is quick to point out that Sydney's checkered past is responsible for many of the qualities he admires in the city's character: ''Much of what 'Sydney' means was set in the difficult early years. . . . In these years you can look for the explanation of our persistent egalitarianism, our complicated relationship with authority, our belief that the government should care for us. The fact that soldiers and convicts starved together forged us in a kind of fire, and in this -- no matter what cruel sign our city was born under -- we were fortunate indeed.''

In the end, Carey's idea of gathering illustrative stories about the four elements proves inadequate to the task of explaining Sydney's complexities, and he leaves Australia with his mixed feelings intact. Certainly his friends remain suspicious of his intentions. ''I know what you're going to do with this . . . book,'' says one. ''You're going to tell everyone how bent we are.'' Well, yes, Carey does let fly at the excesses he finds. But over all he is remarkably fair to the city he left years ago, acknowledging that the forces that shaped it have produced both monstrosities (the Central Business District) and triumphs (the Opera House). And it's not as if an attempt to whitewash Sydney's past could be successful in any case. ''History,'' as Carey writes, ''is like a bloodstain that keeps on showing on the wall no matter how many new owners take possession, no matter how many times we paint over it.''