Fifty years ago, on July 13, 1955, Professor John Dunne delivered his presidential address to the annual meeting of the Royal Medico-Psychological Association in Dublin, focussing on the contributions of ‘the physical sciences to psychological medicine.’ In his address, Professor Dunne discussed (a) the principle of conditioning, and the work of Hans Selye, especially in relation to ‘General Adaptation Syndrome’ and the role of stress in producing psychosomatic symptoms; (b) cybernetics and the generation of partial models of cerebral functioning, such as Grey Walter's Conditioned Reflex Analogue and the Electronic Delayed Storage Automatic Computer of Cambridge and (c) the development of integrated, holistic models of cerebral functioning, that took account of advances in both physical medicine and psychoanalytic thought. Professor Dunne placed particular emphasis on the importance of basic scientific research and the development of broadly based models of psychiatric care, both of which were to play critical roles in the development of more scientifically-based, bio-psycho-social models of service provision in the decades to follow.