After his army career in 1917-1918, and a graduation in history in 1921, Bion decided to study medicine, and gained his medical and surgical qualifications in 1930. In medicine the “biomedical model” was the dominant one during the late nineteenth and into the twentieth centuries (Double, 2007); this model assumes disease to be fully accounted for by deviations from the norm of measurable biological-somatic variables1 (e.g. Alexander, 1939; Engel, 1977). In a seminal paper George Engel (1977) stressed the need for a new mainstream outlook in medicine – the bio-psycho-social model – which takes seriously into account the psychological and social components unaddressed by the reductionist biomedicine. Almost thirty years earlier, Bion (1950) had proposed a model for comprehending diseases in which social, psychological and physical components are intertwined.2 And at the end of his series of papers on groups he remarked challengingly, “The only point about collecting a group of people is that it enables us to see just how the ‘political’ characteristics of the human body operate” (Bion, 1951, p. 131). The bio-psycho-social model had been introduced into medicine in the twentieth century long before Bion’s (1950) and Engel’s (1977). According to Double (2007), Engel’s bio-psycho-social model is basically a renamed and reanimated version of Adolf Meyer’s holistic psychobiological approach initiated around 1920.3 In the 1920s, too, in the UK, Hugh CrichtonMiller, the founder of the Tavistock Clinic, aimed at a “unified psychosomatic approach to diagnosis and treatment” (Armstrong, 1980). Bion drew a great deal from Crichton-Miller’s ideas, and also to the momentous research publications of Wittkower (1949) on life-stories of psychosomatic patients, and of Halliday (1948) on social epidemiology of psychosomatic diseases. In this chapter we will address the wider context in which Bion’s biopsycho-social approach proposals emerged in 1950 apparently quite abruptly in his writing, and quickly waned as he moved from the Tavistock Clinic to his dedication to psychoanalysis.