Dr Stewart was educated at Sir George Monoux Grammar School, Walthamstow and studied medicine at University College Hospital, London; he qualified MB BS (London) and MRCS, LRCP in 1947.
In 1948 he became a general practitioner in Watford and became interested in the use of hypnosis in general practice. This led him to train as a psychoanalyst. He qualified in 1961 becoming a member of the British Psychoanalytic Society in 1963. In 1965 he became a clinical assistant in the Department of Psychological Medicine, University College Hospital, then consultant psychiatrist at the Paddington Centre for Psychotherapy and finally consultant psychotherapist at the Tavistock Clinic until his retirement in 1989. He was elected MRCPsych in 1971 and was elevated to the Fellowship in 1978.
He was a prolific writer, publishing several papers, mainly of psychoanalytic importance, and two books: Psychic Experience and Problems of Technique (1992) and Michael Balint, Object Relations Pure and Applied (1996).
Dr Stewart died on 25 June 2005. He is survived by his wife Joy and three children.