It is hard to change the world for the better, but it can be done. The secret, according to the influential book The Tipping Point, by Malcolm Gladwell, lies in the nature of epidemics, which grow slowly and imperceptibly at first, like tiny flickering flames, before bursting forth as raging infernos.
More often than not, change in society follows this volatile pattern, which is why the grandiose schemes of politicians so often fail, while initiatives with modest beginnings can sometimes reach the tipping point and end up capturing the hearts of a generation.
It is a model that comes to mind when listening to staff and pupils at Bathgate Academy in West Lothian, where a whole school initiative with the potential to spread its beneficial effects much more widely was launched this session.
Its positive living initiative began with a negative: the widely-reported observation that children in Scotland are more sedentary, unfit and overweight than ever, with lifestyles and eating habits that make their life expectancy less than their parents' for the first time since records began.
The traditional focus on academic achievement to the exclusion of other lessons - such as how to live long and prosper - means schools must accept part of the blame for this, says headteacher Joe Boyd. "There is little point in gaining a clutch of Highers and dying at 50 because your lifestyle was an uneducated one."
However, the tension between academic and physical development is more apparent than real, says depute headteacher Douglas Short, who points to studies showing that children who participate in daily physical activities and sport not only gain better health, fitness, discipline and enthusiasm.
"They also perform better in other subjects than their colleagues, despite spending less time in class on them," he says.
Less class time on English and maths to allow more for sport is not an option for a state school, so Bathgate Academy has devised more creative tactics for improving the lifestyles of its pupils.
Progress to date has been in unforeseen and sometimes surprising directions, says Mr Boyd. "When you start something like this different people get involved and before you know where you are things are going on that weren't originally planned and that you did not expect to happen."
School inspectors have recently been taking an interest and the First Minister, Jack McConnell, has written to Bathgate Academy to say that he is "greatly encouraged by the approach".
The examples of effective social change in The Tipping Point - which range from a drastic reduction of crime in New York to fashionable demand for a particular brand of shoe - all share a few common features: most striking is their modesty. To launch a social epidemic, Gladwell observes, resources need to be concentrated on a few key areas and influential people. Bathgate Academy's initiative fits this pattern.
With no additional funding, it has focused on the appointment of a full-time health co-ordinator, the organisation of a month of extended curriculum events and the provision of sports and other physical activities at break times.
"One boy told me he liked being able to watch the other kids playing football instead of going up the street for a cigarette," says Mr Short.
"It's a start."
All the key players in Bathgate Academy's positive living team, from Mr Boyd to the first-year girls who have surprised themselves by giving professional presentations at prestigious conferences, share a belief in persuasion rather than coercion. "To make this kind of thing work, you have to take as many people along with you as you can," says Mr Boyd.
Health co-ordinator Nicky Grant has a passion for spreading the benefits of physical activity and a positive approach to life. Her quiet manner conceals her achievements. Ms Grant is Scotland's most-capped female football player, with 85 appearances so far. Contributors to an Internet football forum describe her variously as "one of the most talented players we have", "brilliant to play alongside" and "the reason that I started football at school".
So it is ironic that her biggest challenge at Bathgate has been finding ways to motivate the girls and switch them on to sport. "Boys are boys.
They don't mind diving out at lunchtime, running around and getting sweaty.
We've got great facilities here, with showers and everything, but the girls aren't using them much yet. Maybe they would if we had a longer lunch-break."
A vital component of Mr Boyd and Mr Short's shared vision of turning the school into a centre of excellence for positive living is their plan to test the health, fitness and attitudes of first-year pupils, and monitor changes - "improvements, we hope" - as they go through the school. Ms Grant's early efforts were directed at this benchmarking exercise.
"We put out a questionnaire asking the kids what they would like to do and how they felt about themselves and their bodies," she says. "We also did a set of physical tests on them, with their permission." These included flexibility, aerobic fitness (the bleep test) and body mass index.
The results, says Mr Boyd were really alarming, even worse than expected.
"What percentage of kids do you think were above or well above average fitness?" he asks. "The answer is none. Only a few had even average levels of fitness, while the majority were fair, poor or very poor.
"We looked at the results from another school in the Borders with a very different catchment area, for comparison. Their results were rather better but still very bad by European standards."
The testing captured the children's interest. However, providing physical activities, and encouraging children to take part to improve their bodies and their self-confidence is only one aspect of the positive living initiative, says Mr Boyd. Providing healthy eating options is another.
"Very often these work for a time, then everybody goes back to chips, biscuits and hamburgers," he says. The reason, he believes, is because such initiatives do not focus on the whole person. Fundamental to Bathgate Academy's philosophy is that physical as well as mental development needs to be addressed in school: the two indeed are inextricably linked.
"Wide-ranging discussion has given us four components to our model for positive living," says Mr Boyd. "They are cognitive health, physical health, ethical health and emotional health.
"We are just beginning to think about the other components. Ms Grant has been looking into tests of emotional intelligence and the team has been thinking about ways of improving children's emotional and ethical health."
The key to the success and sustainability of the initiative, the team believes, lies in this integrated approach, not just because it takes account of the brains, bodies, feelings and morals of different children but also, more subtly, because it takes account of the attitudes, ambitions, interests and aims of different teachers.
"If the English and maths departments, for example, see this as just a physical education initiative, it will die," says Mr Short. "We have to get as many teachers on board as we can.
"You might think we would be spreading our efforts too thinly if we tried to cover all these aspects. But unless we do, we won't carry the whole school along with us. If this is going to work the majority of teachers have to be engaged."
Principal teacher of art Linda Campbell agrees. "PE teachers can be a bit intimidating for a lot of kids. They like to see somebody like me, an art teacher, getting involved in fun runs and physical activities. They ask why I'm doing it and I say because it makes me feel good about myself.
"The big challenge, I think, is getting the positive living message out to parents and the wider community."
First-year pupils Laura Greer and Brionna Wilson, who are experienced presenters of the philosophy to others, are not reticent about their long-term aspirations.
"It's not going to be much good for Scotland if just one school is fit and doing lots of exercise," says Laura. "If another school sees what we're doing and thinks it's a good idea, they might try it, and then other schools could see and they could try it, until eventually everybody was doing it."
This process has begun, says Brionna. "There was another school in West Lothian at the conference we went to. So now we are finding out more about what they do and they are finding out more about what we do. Then we will use each other's ideas to make our own better."
The Tipping Point advocates that the world is not immovable and implacable.
"With the slightest push in just the right place it can be tipped."
Bathgate Academy is pushing in the right place.
HAVE YOUR CAKE ...
Bathgate Academy's recipe for reduced sugar, wholemeal chocolate fairy cakes. Makes six.
50g self-raising wholemeal flour
40g caster sugar
Preheat oven to 170C, gas mark 4.
Sift all the dry ingredients into a large bowl, add the fat, egg and water and cream with a wooden spoon.
Place six paper cases in a bun tin. Divide the mixture evenly between cases. Bake for 15-20 minutes until well risen and springy.
DO SOMETHING FOR YOURSELF: GET ACTIVE, EAT WELL
March was health promotion month at Bathgate Academy, organised by principal teacher (curriculum) Roslyn Fraser, an enthusiast for a school-wide health policy - "for staff too".
"Our aim during the month was to involve as many school departments as possible and to offer as many ways of promoting good health as we could."
Teachers and senior pupils were able to try reflexology, pilates, yoga, fitness testing, salsa dancing, skiing, kickboxing, assault courses, psychotherapy, hypnotherapy, healthy cooking, homeopathy, beauty treatments, massages and blood pressure and diabetes testing.
The climax of the month was a sponsored walk or jog around Arthur's Seat which, together with a whole-school sponsored workout, raised pound;5,500 for the Jaipur Limb Foundation and Children with Cancer and Leukaemia.
"The month was a huge success and will be repeated with more options," says Ms Fraser.
"People sometimes don't realise that healthy living doesn't have to be about denial or imposing some kind of harsh regime. The letter we sent to parents, for example, contained a recipe for chocolate fairy cakes.
"If all you do is tell people they have to stop doing things, you will never get anywhere. You have to be positive and the message is simple: Do something. Get active. Eat well."
For more ideas see www.tes.co.ukgetactive