In times of entrenched social upheaval and multiple crises, we need the kind of social theory that is prepared to look at the big picture, analyse the broad developmental features of modern societies, their structural conditions and dynamics, and point to possible ways out of the crises we face. Over the last couple of decades, two German sociologists, Andreas Reckwitz and Hartmut Rosa, have sought to provide wide-ranging social theories of this kind. While their theories are very different, they share in common the view that the analysis of modernity as a social formation must be kept at the heart of sociology, and that the theory of society should ultimately serve to diagnose the crises of the present. In this book Andreas Reckwitz and Hartmut Rosa join forces to examine the value and the limits of a theory of society today. They provide clear and concise accounts of their own theories of society, explicate their key concepts - including 'singularization' in the case of Reckwitz, 'acceleration' and 'resonance' in the case of Rosa - and draw out the implications of their theories for understanding the multiple crises we face today. The result is a book that provides both an excellent introduction to the work of two of the most important sociologists writing today and a vivid demonstration of the value of the kind of bold social theory of modern societies that they espouse.