These essays not only describe the major changes in British society in recent years, but seek to understand and explain what is happening. One of the themes running through this book is that, while there have been rapid changes in overall levels, there have been slower changes in relativities, and this analytical distinction is absolutely fundamental to a proper understanding of contemporary society. The book also considers the wide variety of mechanisms that underlie these changes, in particular processes of social interaction. The complex and often ill-understood nature of these mechanisms may be a major reason why so much social reform has proved ineffective. The verdict on social reforms in education, gender inequalities and ethnic inequalities is rather negative; and sociologists have long been concerned about the unintended consequences of social action, and in the policy field these are frequent. By highlighting the complexities of the causal mechanisms, sociological research can make a major contribution to policy and public debate. While these papers do not claim that sociology will provide all the answers, they demonstrate that it has made real progress in understanding the social changes that Britain has experienced in recent decades.