The wellbeing approach offers a clear solution to the basic questions in political philosophy and moral philosophy. Crucially, it provides a single overarching goal. Coherent decisions require an overarching goal, for if you have multiple goals, they may point in different directions. Aristotle recognised this but modern ’utilitarianism’ dates back to Jeremy Bentham. According to the Benthamite approach, decisions should aim to maximise the discounted sum of future wellbeing.

This is already the approach of many health policy-makers. However others believe that it is especially important to raise the wellbeing of those whose wellbeing is low. This ’prioritarian’ approach suggests looking for new policies especially in those areas which account for the most misery (on which evidence exists), and giving especial weight to the reduction of misery.

There have been many criticisms of the wellbeing approach, which the chapter discusses and tries to answer – consequentialism and rights, the experience machine, adaptation, and the nanny state. Readers who accept those criticisms are challenged to come up with an alternative philosophy that is operational.

If you were not you but about to be born, where would you choose to be born? This book argues that the best society is the one where people feel best about their lives – where they have the highest ’subjective wellbeing’. It shows how wellbeing can be measured and then explained.

This introductory chapter summarises some key findings about the causes and effects of wellbeing. Key personal factors explaining wellbeing include mental health, human relationships (including work) and (less important) income. Key social factors include the quality of citizens’ behaviour, of government, and of personal freedom in your country. The book shows how, using this information, people can improve their own happiness and that of others and how governments can have the wellbeing of the people as their operational goal. Governments have every incentive to do this because wellbeing affects how people vote more than the economy does, and because wellbeing is also hugely beneficial to other goals like life expectancy, educational achievement and productivity. The science of wellbeing is totally inter-disciplinary and of great value to students of psychology, social policy, economics, politics and philosophy. It is central to answering questions about sustainability and ’beyond GDP’.