The treatment of menopausal and postmenopausal symptoms is a focus of considerable debate, on account of both the medical and social factors involved. And perhaps the cause of the greatest current interest and concern is not so much the effectiveness of present-day treatment but its safety. Opinions on the subject vary; and to resolve the arguments we must turn to the results of scientific experiment, both the clinical and biological. It is only by comparing experimental results that it is possible to move forward, albeit slowly, towards a generally agreed consensus based upon objective scientific data. It is for this reason that we are particularly grateful to Ayerst Laboratories whose support and help have enabled us to turn our original proposal for an International Symposium into a reality. We are also grateful to the publishers for the efficiency with which they have organized the publication of the Proceedings. It is our hope and that of all the distinguished participants that all readers of this volume will be able to find something in it which will stimulate further thought and discussion - even though they may not necessarily agree with all the conclusions expressed - for the success of a Symposium turns not only on the subject under examination but also on the quality of debate and discussion it encourages.