Paul Collier, professor of economics and public policy at the Blavatnik School of Government, Oxford University: We need wisdom. It comes from synthesising the generic knowledge of the expert with the contextual knowledge of the practitioner. For a society to continue functioning well, it will occasionally have to change its values as better, new ideas spread across its communities. Sometimes the spread of successful new ideas needs leadership; sometimes it can happen by osmosis. We thrive when we have some purpose in our lives other than self-indulgence, and the ability to contribute to it. Contributing to common purposes provides the dignity of mutuality: everyone has an active role to play. But to contribute, people must be in a position to do so, and after decades of negligence, many are not. Rectifying that neglect is the foremost practical priority.  It is about willing compliance in national purposes that have been agreed through a participatory and inclusive political process. No state can be effective without it.