“Positive psychology”, pioneered at Cambridge and Harvard, has caught the imagination of the ever-original Anthony Seldon.

I am not here to mock: what he has spotted is the miserable fact that school education is unbalancing some of its most “successful” pupils. The problems of low academic achievers are often under the spotlight, and rightly; but that is no reason to ignore those who hike up the school’s league-table place with their A*s but who in person are resentful, over-anxious or plain depressed.

If “positive psychology” can cheer them up, while simultaneously offering comfort and hope to the D-graders, good luck to it.

One does worry a bit about the textbooks, though. We know where the Nile and the Danube are, we can check mathematics against reality, but no one quite knows what happiness is.

Well-being, in this self-conscious sense, is a newish science: we are bombarded with factoids from self-help manuals, surveys and even the Cabinet Office, which lately said with weird confidence that in terms of contentment getting married is “equivalent to a pound;72,000 pay rise”, which mainly makes you wonder whether the reverse applies.

We are told that the UK is sixth in the European life satisfaction league (Danes are cheeriest, Belgians miserable. Set up positive psychology field trips to Belgium to work out why).

Go further back and higher up for your definition of happiness, and the waters grow muddier yet. Epicurus said it was all about pleasure (Saturday night binge drinkers and E-fuelled ravers would heartily agree). Seneca found it in stoicism, St Augustine and Buddha recommend moral living and union with God.

Kant reckoned it was a matter of making yourself worthy of happiness, Schopenhauer decided that high art and charity do the trick, and that wealth makes you miserable (so spend it all on drinks for Epicurus?).

Bertrand Russell said the “Conquest of Happiness” comes through hard work , and the Dalai Lama that warm, close caring for others brings inner peace (but if you’re gay, then that’s “wrong, full stop” so it’d better be celibate closeness). The epigrammatists contradict one another, too.

Jefferson averred piously that it lies in the bosom of the family, and George Burns growled “Happiness is having a large, loving, caring, close-knit family. In another city.”

See? You’ve got the makings of a five-year philosophy course before you even start. The only thing that most of the thinkers agree on is that love counts for more than money, and you can sum that up with a chorus of “Can’t Buy Me Love” and a reading list. Might as well hand out copies of PG Wodehouse and spend the period catching up on your paperwork.

Also, there is clearly a risk that modern educators will seize only on the most current and politically correct ideas of happiness, and shy away from the bleak dutiful ones. Life, after all, contains hard choices: if you’re in a dull marriage and fall in love outside it, should you pursue your likely happiness if it makes your children’s less likely?

If you are happy and secure in your school but it doesn’t offer the subject you most need at A-level, is it right or wrong to move to a strange college a 10-mile bus ride away? How much personal happiness is negotiable when you have a burdensome relative or unpleasant job?

Even the money business is contentious. “Money doesn’t bring happiness”, they all say, yet all research suggests that having too little money makes you stressed and anxious in a modern consumer world.

Meanwhile, the rest of the modern school day has the spectre of money - future earnings - hanging over it: why else do we urge children through “qualifications” and into university? Why else do we look back so nervously at the Seventies educators who said that learning mattered less than becoming a lovely person?

It’s a huge syllabus. It is also potentially a controversial one. If you start to preach that happiness is a butterfly to be chased, a box to be ticked, you open many cans of worms. The real peril, though, if the idea spreads, is that Ruth Kelly orders the Qualifications and Curriculum Authority to start assessing and scoring schools on their “delivery” of happiness instruction, monitoring a daily SQ (smile quotient) by random serotonin checks and hidden cameras. Perhaps, after all, schools should just think about going back to the amateurish old ways of teaching happiness.

You know: community singing, outdoor play on grass with no scores or coaches, lessons where you actually made things with your hands, teachers free to devote a whole history period to exciting flights of narrative miles off the syllabus... oh, and school trips, nature walks, quiet libraries, proper dinners with time to eat them...