The author tries to illuminate H.S. Sullivan's complex professional identity. With E. Fromm he shared a basic humanistic orientation, and also the project of creating an interdisciplinary new science of man. This is the perspective he inherited from W.A. White, who tried to make psychoanalysis a major ingredient of psychiatry and social science. Sullivan's pioneer work with schizophrenic patients changed the prognosis of these patients, represented the basis of his interpersonal theory of psychiatry and of his collaboration with Chicago social science. Not only is the epistemological sophistication of his definition of psychiatry— which includes the biological, intra- psychic, cultural and social dimensions—very relevant today, but so is the work he conducted, through the Washington School of Psychiatry (1936) and the journal Psychiatry (1938), with the aim of creating what he called a “psychiatry of peoples”, leading to world peace and greater social justice. In his view, psychoanalysis was more than a profession: it was a fundamental instrument of personal, cultural and social change.