An ancient egg hatched, a magpie was born

If you are rich beyond the dreams of avarice, rich unto the third and fourth generation, gold mines and railways rich, there are really only two ways to become (relatively) poor. You can gamble, or you can collect things.

I do not underestimate the pleasure of gambling, an insidious and wicked pleasure that relies on the incorrigible human belief that things are about to get better. The next card, the next throw of the dice, the next spin of the gleaming metallic wheel, and the gambler knows his luck will turn and he will win: if he can hang on long enough.

The power of gambling to dispose of huge sums of money is exceeded only by collecting. Collecting has more status, although it may be as childish a pursuit as wanting to complete a series (stamps, Dinky toys, matchbox labels) or as ruthless as the desire to corner the market (remember the Bunker Hunts and silver?). The scholarship attached to objets d'art, the soft interiors of antique shops, the shadowy piles of rugs in carpet shops, the glittering colours of toys, jewels or ephemera add aesthetic and intellectual validity to what is often a dirty business.

Whole categories of art have been tainted by the greed that motivates their acquisition. Japanese and Australian millionaires bought Renoirs and Van Goghs because they believed Impressionists were safer than gold bullion (wrong]) and hoped some quality would rub off on them (doubly wrong). Other collectables fall so thoroughly out of fashion that nobody bothers with them any longer: it is hard to believe that tulip bulbs commanded fortunes in 17th-century Holland. Rarely is the passion for collecting motivated solely by love of the objects in question. And, because this is a very private passion, such collections are seldom on public view.

Hurry, then, to the Royal Academy in Piccadilly, London, where In Pursuit of the Absolute: Art of the Ancient World ends on 6 April. It is the fruit of 44 years' devoted collecting by one man, George Ortiz.

It was in his early twenties, during a visit to Greece, that Ortiz felt he understood for the first time what is meant by 'the absolute', and in so doing, found the truth he had been searching for. 'Man's physical birth took place in East Africa,' he says, 'but his spiritual birth occurred in Greece around the fifth century AD. The ancient Greeks were the first to believe that the universe is anthropocentric - that it exists not for the benefit of God or gods or animals or the ecosystem but for man. They further believed that man is a rational being, capable of goodness, justice and beauty.'

This humanist ideal has informed Western thought and art ever since, and is the impulse behind the Ortiz collection.

The young George Ortiz returned to Paris and made his first purchase the next year, 1950. With perfect symbolism, it was an egg: a Cycladic marble egg 4.5cm high, dated between 3200-2100 BC; and from that 4,000-year-old egg was hatched this great collection. Next, he bought a tiny amber hippo from the Nile, 1800-1450 BC; then a 4th-2nd- century BC bronze figure.

Since then, the acquiring and admiring of ancient art has been his ruling passion. Today, says Ortiz, 95 per cent of his wealth is tied up in the collection - to an extent that family life has suffered at times and his wife becomes very upset. But the true collector must buy what appeals to him: 'The great moment is the moment of acquisition - it's like falling in love.' He feels himself to be a magnet to which these old, rare and beautiful objects are mysteriously attracted. Ortiz speaks of them 'coming home' and finding their rightful place in his collection.

He insists that he is an amateur and believes his 'eye' was best in the beginning, when he responded to objects most naturally. Although highly knowledgeable, he disclaims scholarship, saying that his response is visceral and emotional rather than cerebral.

Indicating a tiny bronze figure, barely three inches high, he will point to the curve of its back, the swell of its breast, the line of its profile, so that object, creator and viewer are united in a communication spanning three thousand years. It is an extraordinary experience that transcends time and comes only with intimate knowledge of each object; and it is for this, the true joy of ownership, that collectors will beggar themselves - and consider the money well spent.