Like many fashionable notions, 'stewardship' is a term which can mean different things to different people. And regulators, who rush to take the concept up, rarely tarry to define it. This book undertakes the task of saving stewardship from the charge of vacuity. It is difficult to think of anyone better than Professor Katelouzou to undertake this task. She has world-wide knowledge of the instantiation of stewardship, has developed an analytical apparatus which is second to none and applies with vigour to this most tricky of problems. Paul Davies, Senior Research Fellow, University of Oxford, Harris Manchester College