I had not yet started my analytic training when I first encountered Isabel's seminal paper, ‘The functioning of social systems as a defence against anxiety’, and, as I worked in the following years in a variety of settings, I found her ideas essential to my thinking about these institutions, and how their ‘systems’ worked. It also formed the basis of my thinking when, many years later, I became Chair of the British Association of Psychotherapists and, subsequently, the British Psychoanalytic Council.

As a newly qualified psychoanalytic psychotherapist, I met Isabel as a supervisor. I was struggling to know how to proceed with a colleague. I had become co-therapist for a group that had been functioning (a debatable description under the circumstances) for a while before my arrival. After six months I felt I could no longer continue with the lack of boundaries and containment and shared my concerns with Isabel. What to say to my