The Philadelphia Association is always linked with the name of R. D. Laing, one of its founders, but very little is known about its unorthodox contribution to the development of psychoanalysis. Founded in 1965, it took as its aim the relief of mental illnesss of all desciptions, in particular schizophrenia. At its inception it was a focus for people, with a diversity of backgrounds and interests, concerned with 'mental illness' and how society defines it. Its members - who included psychoanalysis, psychiatrists and artists - developed a philosophical critique of psychoanalysis grounded in phenomenology, and an 'anti-psychiatry' critique of the institutional treatment of the mentally ill. They favoured the setting up of therapeutic community households of which the best known was Kingsley Hall. The PA was then very much part of the counter culture - it staged, for example, the famous Dialectics of Liberation Congress at London's Roundhouse in 1967. The psychotherapists who currently belong to the Philadelphia Association continue to work with community households and to offer a psychotherapy training. Here the authors share their innovative and distinctive approach on a number of interrelated themes: the herapeutic community and differend ways it can be understood; work with deeply regresed patients; the concept of identity in a social context; the debate between Lacan and Derrida on Poe's 'The Purloined Letter'; the phenomenology of knowledge and transference and authority. Together, they offer a cogent critique of many psychiatric and psychonalaytic assumptions. The contributors are Robin Cooper, Joseph friedman, Steven Gans, John Heaton, Chris Oakley, Haya Oakley and Paul Zeal. They are all psychotherapists and members of the Philadelphia Association.