It is now possible to quantify people's levels of happiness pretty accurately by asking them, by observation, and by measuring electrical activity in the brain, in degrees from terrible pain to sublime joy.

Is anyone serious about the politics of happiness? David Cameron dipped a toe in the water, using the word lightly, but denying the hard policies it implies. Labour shies away from it, but should take up the challenge.

So what really works? Treatments in jail do some good, but it's mostly too late: finding a family and a job or just growing older make most prisoners eventually give up crime.

The strongest predictor of unhappiness is anyone who has had a mental illness in the last 10 years. It is an even stronger predictor of unhappiness than poverty - which also ranks highly.

There is all the difference in the world between teaching children about religion and handing them over to be taught by the religious.

In the polls, over 80% support the right to die and have done for the last 25 years. Even 80% of practising Catholics and Protestants support it, plus 76% of Church Times readers.

One in six people suffer depression or a chronic anxiety disorder. These are not the worried well but those in severe mental pain with conditions crippling enough to prevent them living normal lives.