Sarah Sands: Scarlett Keeling died at the roll of a dice. It's a perilous game

Each human tragedy has its socio-economic dimension. The terrifying abduction of Shannon Matthews is coolly discussed as a portrait of a debased white working class, with its multiplicity of fathers and attendant social workers. When Madeleine McCann went missing we rapidly absorbed the context. The parents were doctors, ambitious, gym conscious, dressed in high street chic. The holiday destination, Mark Warner in Portugal, was family minded and middle class. The McCanns felt safe to leave their children in the room, because they were among their own people.

Fiona MacKeown was as trusting of her own way of life. Goa was the geographical affirmation of her identity. Gentle, free, non materialist, non judgmental. True to her beliefs, she has rejected the conventions of work, family structure and social aspiration. She has nine children by five fathers.

One person's small holding is another person's squalor. The shack that she calls home looks wretched to me, but I was not very shocked by the interior shots of Scarlett's bedroom. My daughter's room is just as untidy. Similarly, I do not share the distaste of many journalists for Fiona MacKeown's hippy appearance. She has a calm beauty and resembles Charlotte Rampling in some photographs. Scrubbed up a bit, the whole family could appear in a Calvin Klein advertisement. The children with their tousled hair and burnished bodies laughing on a beach with their carefree mother. It would be an alpha ideal if they had a few million in the bank and a Bryanston education.

Perhaps it was negligent to pull children out of school for six months to go travelling, but Fiona MacKeown was only following the advice of Times columnist Mary Ann Sieghart. The gap-year students I know have animated debates about whether their lives should be "on or off road." They are pouring into African orphanages and Indian villages in search of different values and meanings. They find little to condemnin Fiona MacKeown's way of life. She has flawless green credentials and is a loving mother.

Yet those same studentss are aghast at her decision to leave a troubled 15-year-old girl to fend for herself among strangers. Her hippy ideology destroyed her common sense. Although she had been a victim of a knife attack herself she persisted in her belief in unerring global citizenship. It is either saintliness or egotism. She judges no one, not even her self. There are official suggestions of parental negligence yet she can find no fault with herself beyond being "trusting." Only agents of institutional authority (i.e. the police) must be blamed.

You would not do it in London, so why would you do it on a drug-strewn beach?

Freedom without maturity can be a terribly dangerous thing. I remember once dropping off my 13-year-old daughter at a peer group party in a local hall. A couple of hours later, the manager of a B&B some miles away rang to say he had a girl with him in tears. I was so grateful for his kindness. Any parent hopes that the stranger who approaches their daughter has good intentions and dreads the consequences if not. It is the ghastly roll of the dice.

The fragmentary final hours of Scarlett's life are utterly bleak. A stoned, drunken, frightened girl tottering about the beach. A man lying on top of her. Her pitiful confidence to a friend that she was sleeping with the tour guide to ensure a roof over her head. Finally, her lifeless young body washed up by the waves.

She may have been a free spirit, but Scarlett was also a child. Fiona MacKeown put ideology before humanity.