Over 5,000 years, states have made surprisingly consistent claims about their duties. They have promised to protect people from threats; promote their welfare; deliver justice and also, perhaps less obviously, uphold truth - originally truths about the cosmos, and more recently truths drawn from reason and knowledge.

Science is, rightly, searching for drugs to arrest ageing or to slow the advance of dementia. But the evidence suggests that many of the most powerful factors determining how you age come from what you do, and what you do with others: whether you work, whether you play music, whether you have regular visitors.

Lots of creativity is and should be solitary.

Everyone knows of great projects that were too dependent on a charismatic individual, or simply too expensive to be replicated.

All real capitalisms are impure hybrids, mongrels mixed with other strains.

All over the world, social innovation is tackling some of the most pressing problems facing society today - from fair trade, distance learning, hospices, urban farming and waste reduction to restorative justice and zero-carbon housing. But most of these are growing despite, not because of, help from governments.

I can think of nothing worse than a think-tank where everybody agreed.