This book contains twelve studies by well-qualified authors, many of them already very well-known in the field of ecumenism. It represents a stocktaking at the end of the twentieth century of "the unity we have" and a reassessment of "the unity we seek." It provides a well-documented overview of the field: a thorough and accessible introduction for everyone with an interest in ecumenism and an invaluable resource for everyone involved at any level. A substantial section charts some of the major ecumenical developments of the twentieth century and some of the new problems that have emerged.