Peter Fonagy is Freud Memorial Professor of Psychoanalysis and Director of the Sub-Department of Clinical Health Psychology at University College London. He is Chief Executive of the Anna Freud Centre, London. He is a clinical psychologist and a training and supervising analyst in the British Psychoanalytical Society in child and adult analysis. He has published over 200 chapters and articles and has authored or edited several books. Joseph Sandler qualified as a psychoanalyst in the British Psychoanalytical Society. He was the Freud Memorial Professor of Psychoanalysis in the University of London and Director of the Psychoanalysis Unit at University College London, and in private practice in London. He was formerly the first Sigmund Freud Professor of Psychoanalysis at the Hebrew University of Jerusalem, Editor of the 'International Journal of Psychoanalysis' and the 'International Review of Psychoanalysis', and was President of the International Psychoanalytical Association.