If you don't want to be disappointed by your first impression of Rio, you should avoid looking around from when your plane first touches down until the moment you feel the warm sand of Copacabana under your feet. But once you're on the beach, open your eyes wide: the girls around you look very much like the ones featured in the tourist brochures. All they seem to want is to be admired and to strike up conversation. That's not to say they're loose (not every one of them, at any rate), but each of them, whether engaged, married, already in love or still a virgin, will give you the impression of being wonderfully available.

If your interest takes a more cultural bent, you don't have to venture far from the beach to meet members of the Brazilian intelligentsia, be it painters, writers, film directors or bossa nova musicians. In fact most of those you meet will tell you they are involved in all these arts at once. They are also politically engaged (left-wing of course) and will happily ditch their girlfriend or the radio on which they are listening to the football match, to inform you of the plight of agricultural workers in the Nordeste and of their exploitation by the Yankees.

After a few minutes (or a few hours if you find it really difficult to unwind) the sight of the ocean, the warmth of the sun and the smiles of the girls will have their effect. It will be your turn to overflow with this indulgence towards others as well as towards yourself that constitutes both the greatest virtue and the greatest fault of cariocas (the term, originally describing a type of parrot, is used by Rio's inhabitants to designate themselves).

Just make sure you avoid staying in your hotel between eight and nine o'clock in the evening, and don't walk out on the street at that time either: it's when the power cuts off, elevators are blocked and chaos reigns at traffic lights. The Brazilian administration can't reach agreement with the Yankee monopolists who built the power stations and who, with characteristic rapacity, refuse to modernise them while the pre-inflationary price of electricity is maintained (that is to say, at well below cost price).

The best you can do is while away this hour in a restaurant where you can dream by candlelight-as long as you have retained enough indulgence to put up with the slowness of service and the mediocrity of the meal.

After nine o'clock and once having downed a cafezinho at the corner bar, you will find the streets of Copacabana filled with sweetness and seduction. You can wander about in complete safety for the rest of the night so long as you keep an eye on the pavement-because sewer covers are not always in their proper place.

As you walk along, you will notice more lovers than in any other city in the world. Rio's couples kiss on the sand, on the benches of the Avenida Atlantica, in the entrances to buildings, on the dark steps leading up to the favelas, in the half-light of the bossa nova clubs, on the worn-out seats of the lotaçaô (the small private buses which always look as if they are dropping parts, and which can be hailed like taxis). You will end up wondering how kissing can take up so much space in people's lives, even accepting that some only kiss for self-interest or for sport, for boredom or for the simple pleasure of physical contact. After a few days, personal experience might teach you that in Rio, men and women often kiss for want of an alternative: hoteliers are not allowed to let out rooms to unmarried couples and the police, which is not very efficient in other areas, is punctilious in this matter.

Unattached girls (fortunately there are still a few left) are potential kissing partners. At every step you'll come across the smiling availability of their glances. And you'll end by telling yourself that the tourist brochure didn't lie: Rio is the city where you would like to spend the rest of your life. You can hang on to this happy outlook for the remainder of your stay as long as you stick to some very simple rules:

1. Don't ever stray far from Copacabana, Ipanema or Leblon, the three residential districts which give onto the beaches. In the Cidade, the business centre, you will only meet people trying to earn a living and that makes them a good deal less lovable. Above all, don't wander about the favelas up on the hills, which are inhabited by wretched under-nourished blacks. If you really want to get an overall picture, take either one of the Corcovado or Sugarloaf Mountain funiculars. On a clear day, the view which greets you will look exactly like the one in the brochure.

2. Agree to every appointment but never turn up, even if the proposing party is a pretty woman claiming to be in love with you or a government minister (indeed be most wary in these two cases). No carioca honours his appointments. But if, at the arranged time, you happen to pass Castelinho, the fashionable Ipanema bistro, you'll stand a very good chance of seeing the person you were supposed to meet (unless, of course, it was there that he or she promised to meet you).

3. Besides, you should realise that a missed appointment does not denote lack of interest from the other party. Next day, you may well meet the self-same minister in his trunks on the beach and make him sign on the spot for the old aircraft carrier that you want to sell him. (This has actually happened: in Rio's military port, one can see a huge aircraft-carrier bought from US Navy surplus. It never returned to sea because the Brazilian navy hasn't got the technicians to maintain it.) What matters is to make the most of the jeito, the enthusiasm which is quickly inflamed and just as quickly extinguished and which characterises cariocas' reactions. If you give the minister the time to say, "I haven't got my cheque-book on me, come to my office tomorrow," you can wave goodbye to your business deal.

4. Above all, in love as much as in business, never appear too persuasive, never show your need to succeed, never engage your ambition or prestige. Tell yourself that, sooner or later, what you want will be served to you on a platter, if only you have the time (and the money) to wait.

I consider myself particularly well-qualified to give this advice because, in my first two weeks in Rio, I did exactly the opposite. This led me to hate the most lovable city in the world and to feel irritated by people who only wanted to make me happy-as long as it didn't demand too much effort.

I looked around on the way from the airport to the hotel: the suburbs of Rio are almost as decayed as those of Calcutta, the centre is almost as run-down as that of Cairo. Even the luxury buildings giving onto the beaches of Copacabana and Ipanema are far from being well-maintained.

I visited the favelas. I didn't see any mulatto girls with long hair and strategically torn rags like in the film Orfeu Negro. Nor was I robbed by bandits as my friends in Ipanema had predicted. I saw women queuing by the wells at the foot of the hills, then carrying the water cans back up hundreds of feet, I saw naked children with swollen bellies, unemployed men sitting motionless on the thresholds of their huts. I saw extreme poverty in the midst of an earthly paradise of lush vegetation against the spectacular backdrop of Ipanema beach and Sugarloaf Mountain.

The difference between these favelas and the shanty towns of Calcutta or Caracas is that here, the poorest live a few hundred yards from the privileged. The two worlds exist side by side according to rules I was unable to understand, as if neither perceived the reality of the other. Nothing stops the young blacks of the favelas from bathing in front of the Grand Hotel Copacabana or from playing football on the beach with the scions of the rich. And you do sometimes see a few blacks, conspicuous for their scrawniness and their rags-but they are only a tiny minority in the crowd of the well-to-do.

It goes without saying that "black" and "poor" are almost synonymous, even if there may be intermediate gradations of skin colour and wealth. Brazilians claim to be free from racism, and it's true that no obvious barrier keeps the races apart. I often saw mixed-race couples who did not seem to arouse particular disapproval. But I never met any blacks who were really well-off, nor did I ever hear of a mixed marriage involving an upper-class family. Doubtless there are unspoken barriers, much more subtle than those in the United States or South Africa, but perhaps all the more tenacious as a result.

In fact, Rio's incongruities only appear as such to visitors who are over-attached to facts and figures whereas, for a carioca, some myths are more real than reality. On the subject of race relations, for instance, it goes without saying that the colonisers' descendants still wield economic and political power (or, in Marxist parlance, the power delegated to them by the Yankees). But as the year comes round, between one Carnival and the next, the blacks prepare for the moment when roles are reversed and the myth gains the upper hand. In every suburb of Rio, the escolas de samba practise their choreographies and perfect their fabulously expensive costumes, generally paid for by politicians who thereby secure the votes of the lower classes and assure the continuation of their office.

When Carnival comes, the slum-dwellers will be the masters of the city: dressed as eighteenth century Portuguese princes and conscious of their physical beauty, they will fill the streets with their frenzied rhythms. The prettiest young women are chosen to impersonate Chica da Silva ("the maid from the forest"), a slave-girl who became mistress and then legitimate wife to Governor Fernando de Oliveira. For the blacks, Chica represents a mixture of Joan of Arc and Madame Du Barry. Folk songs describe her as surrounded by Portuguese serving ladies, or else embarking on a galleon loaded with gold for a triumphal voyage to the country of her erstwhile masters. In fact, veneration for Chica is common to all cariocas, white as much as black, even if my intellectual friends of Ipanema acknowledge that her road to power didn't quite correspond with Marxist orthodoxy and that her example cannot be recommended to the toiling masses.

I remember discussing this very subject during the afternoons I spent sitting outside Castelinho, checking my watch and waiting for my appointments to show up. I had decided to do a reportage on the rites of macumba in which I saw the quintessential manifestation of the Brazilian spirit. Everyone I had met at Castelinho declared themselves to be specialists in the field, and all of them promised to help. Then, as usual, they kept me waiting...

I knew that macumba was the true-if unofficial-religion of the majority of blacks and half-castes of Brazil. Whites participate more rarely in these rites, but they still seek out the macumbeiros for help with their health or love problems. In the state of Bahia, where African traditions are best preserved, this religion is closer to its roots and is called candomblé. Elsewhere it manifests itself as a mixture of animism and witchcraft involving entrancement and blood sacrifice before altars consecrated to African deities but also dedicated (in a kind of sop to the church) to Christian figures like Jesus, the Virgin Mary and the Saints. Some rituals are practised openly: from my bedroom window after nightfall, I've often seen black women digging small holes in the sand of the beach to light candles in honour of Iara, Senhora das Aguas, who unites the attributes of an African Aphrodite and the Virgin Mary.

However the collective trances and animal sacrifices, which are tolerated by law though banned by the Catholic church, take place in the poor neighbourhoods and only in secret. Without the help of an insider, I would not have been able to witness one, still less take photographs. Every morning, my friends from Castelinho promised to take me there-and every evening they let me down.

One afternoon, when I had almost given up on this project, I was favoured by a stroke of jeito. I happened to be with a female friend in a taxi driven by a black man. She was just asking the driver about macumba when he spotted Nillo, a well-known macumbeiro, in the car in front of us on the Avenida Atlantica. After a racy pursuit, we managed to catch him up and start a conversation. In the evenings which followed, from macumba to macumba and from jeito to jeito, I did the rounds of all the terreiros of Rio, accompanied by my friend acting as interpreter.

The ceremonies take place at night in places called terreiros, which might be a covered hall, the courtyard of a building or simply an open space in a favela. Some macumbeiros specialise in black magic, which invokes evil spirits and aims to harm those to whom the client wishes ill. Others practise exclusively white magic, umbada, which calls on beneficent powers to get favourable interventions.

In both cases, these rites are not meant to bring the faithful closer to a divine entity, as in the monotheistic religions, nor help them attain a higher spiritual level, like in Oriental practices: their only purpose is to establish a link with occult powers in order to obtain help or favours from them.

These powers are male or female and are ordered in groups of two, three or seven. Each of them corresponds both to an African divinity and to a figure out of the Christian hagiography, and each is represented by alchemical and astrological symbols. Thus Iara (or Iemanja), goddess of the sea, corresponds to the Virgin Mary; her stone is sapphire, her day Sunday and her colour azure. Urubata (or Ogum) is the god of war and corresponds to St George; his gem is ruby, his day Wednesday and his colour vermilion. Oxossi (or Aimoré), is the god of hunting and corresponds to St Sebastian, Omulu (or Anhanga) is the god of plague and corresponds to our Lazarus.

To maintain the balance between male and female forces, the macumbeiro is assisted by a woman. The officiants-the equivalents of our mediums-stay within a circle marked in chalk on the ground. Supplicants stand outside the circle. The macumbeiro invokes the caboclos (the occult powers) by presenting their symbols-for example, fire, water, some mineral substance or the blood of a sacrificed animal-to each power in turn. To help induce trance, the mediums swallow a powerful brew and inhale from an enormous cigar. Then they start whirling their bodies and their movement becomes faster and faster. When trance occurs, it is seen as a manifestation of the caboclo temporarily incarnated in the medium. This finds expression in frightful grimaces and uncontrolled agitation of the limbs, sometimes so violent that assistants have to surround the person possessed and cushion their movements. As paroxysm approaches, the macumbeiro authorises the supplicant to invoke the incarnated power and express his wish.

I was particularly struck by the mediums. They are generally female, sometimes quite young and pretty, and take part in these rituals two or three times a week without any material or social incentive. For anyone watching their faces, their experience seems to be one of great suffering, quite apart from the rather unappetising preliminaries like the cheap alcohol, the nauseating smell of the cigar and the blood from the sacrificial beasts which the macumbeiro pours into their mouths. But they come out of trance less exhausted than one might imagine, smiling vaguely as if filled with an inner peace.

I can only say that these ceremonies left me perplexed: all the more so because, on the eve of my departure for Senegal, my Brazilian friend confessed she had wanted to prevent my leaving and had asked the caboclos to keep me close to her. I was duly touched by her intention, but I could not change my itinerary. I left as planned and I confess I felt a certain relief when take-off proved trouble-free. However, in mid-Atlantic, I was seized by violent shivers. A French doctor in Dakar was summoned urgently to my hotel room and declared I had a fever of more than 105. During the week it took me to recover, I told myself that, not unlike Wagner's Tannhäuser, I had narrowly escaped from love's magic mountain.