The 30^th Hay Festival coincides with the 500^th anniversary of the reforms proposed by Martin Luther. To celebrate this important milestone in Western critical thinking, we have asked a number of thinkers to present a reform that is relevant today. In the 21^st century, most of the planet’s population lives in urban areas and there are ever more megalopolises and cities with millions of inhabitants. In this context, how does living in a city affect humans? If our surroundings determine our quality of life, why not make cities more human? Deyan Sudjic, Director of London’s Design Museum, will propose a new concept of city.