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.

Inequality makes everyone unhappy, the poor most of all, and that is well within the remit of the state. More money gives less extra happiness the richer we get, yet we are addicted to earning and spending more every year.

Could a government dare to set out with happiness as its goal? Now that there are accepted scientific proofs, it would be easy to audit the progress of national happiness annually, just as we monitor money and GDP.

Working lives are for the state to influence. Unemployment makes people unhappy. So does instability.

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

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.

My mother begged doctors to end her life. She was beyond the physical ability to swallow enough of the weak morphine pills she had around her. When she knew she was dying I promised to make sure she could go at a time of her choosing, but it was impossible. I couldn't help.