If you see me lying in the street...

As a child attending my village's state-run Church of England primary school Imust have heard the parable of the Good Samaritan more than 50 times. Whatever your reservations about Christianity, it's hard to deny that the Samaritan's story is a crystal-clear illustration of unequivocal morality in practice. Its simple message is that divisions of race and creed should be as nothing when you hear the louder cry of common humanity in peril, and that there is only one correct course of action when you see a battered person slumped on the side of the road - you must tend to them.

As a child attending my village's state-run Church of England primary school Imust have heard the parable of the Good Samaritan more than 50 times. Whatever your reservations about Christianity, it's hard to deny that the Samaritan's story is a crystal-clear illustration of unequivocal morality in practice. Its simple message is that divisions of race and creed should be as nothing when you hear the louder cry of common humanity in peril, and that there is only one correct course of action when you see a battered person slumped on the side of the road - you must tend to them.

The abandonment of school assemblies and religious worship may be one small cause, but something must account for the current lack of moral clarity, even when dealing with the least ambivalent of situations. I wonder what excuses, if any, ran through the minds of the drivers of a dozen or so cars which quite literally "passed by" the prostrate body of a young woman with serious head injuries as she lay in the road in Sidcup, Kent, 10 days ago. I don't mean that judgementally: I really want to know what had so anaesthetised their emotions that they did not think a critically injured 25-year-old worthy of their intervention - that they did not think "She could be my sister" or "my daughter".

Their behaviour stems partly, I suspect, from the prevailing climate of moral equivocation where all suspect actions, from petty theft to suicide bombing, can find some degree of social justification. Doubtless one of the Sidcup drivers reflected: "I didn't stop because I'm a single dad with ME and twin toddlers with Attention Deficit Disorder and there seemed a good chance a maniac was lurking around with a hammer." Such an excuse often disguises some less palatable truth, such as "I thought she was a drug-addled prostitute and, therefore, her life was worthless". Everything about modern life discourages "getting involved". When even the police caution against intervention, those who do spring to the aid of a fellow being are quickly isolated by the myopic pack.

My sister was travelling on a Victoria Line tube train 10 years ago when a muscular black guy started hurling abuse at the black girl sitting next to her before aiming a series of karate kicks at her face. My sister said it was clear that he was mentally ill and didn't know the girl, who was screaming with terror. My sister shouted at him to stop and then shielded the girl with her own body. All the while male commuters on a packed peak-time train looked elsewhere. Only when the attacker jumped off at Seven Sisters station did a few shamefaced men approach and say: "Are you all right?"

Similarly, my sixty-something uncle was the only person to step in when a woman was being slapped around by her boyfriend at a party. The man punched my uncle so hard that he knocked him out, split his lip and bust his nose, and he stopped breathing for some seconds. He was in hospital for several days. The police treated the incident as if some silly old dear in a bow tie had stuck his nose in where he was not wanted and got his just deserts. Both these situations occurred in busy public places. No wonder the woman in Sidcup didn't stand a chance.

The demise of public transport and the supremacy of the car has been one of the last century's most malignant legacies, further isolating the individual from any sense of social responsibility. Automobiles have increasingly become extensions of our sitting room - with all their security devices, communication and sound systems - from which you can safely gawp at the disasters that befall others without feeling any onus to help. Slowing down to stare at the crash on the other side of the carriageway has become a diverting supplement to the constant TV glut of misfortune and suffering served up as entertainment. Fact or fiction, Crimewatch UK or Casualty, the beheading of hostages or such dramas as last Sunday's Dirty War, the strongest emotion that anyone feels nowadays is relief that whatever horror is on view is not happening to them or their loved ones.

Had the Good Samaritan been cocooned in a Mercedes 4x4, he would have put his foot on the gas and gone home to watch how the story ended on the Ten O'Clock News.