This unique book ranges across the physical, biological and social sciences in the development of its primary theme, that there are nine major ‘integrative levels’ which can be recognised. The term integrative levels was first used by Joseph Needham in 1937, and has two key features. The first is that members of a given integrative level are unified entities and the second is that a member of one level is commonly composed of parts which are members of the next lower level. Thus fundamental particles form Level 1, while Level 9 is that of sovereign states. This theme has been developed by Max Pettersson in a book which explores the many links between the physical, biological and social sciences, reaching wide-ranging and sometimes unexpected conclusions.