Eric R. Kandel, the Nobel Prize winner of 2000 in physiology and medicine, emphasises five scientific principles of which psychiatrists must be aware and which are presented and critically analysed in this article. Kandel states that professional requirements for future psychiatrists will impose a greater knowledge of the structure and functioning of the brain, and that the rationale for the unique domain that psychiatry occupies within academic medicine is the analysis and understanding of the interaction between the social and biological determinants of behaviour. The work of a psychotherapist is based both on scientific knowledge and, to a large extent, on an empathic understanding of the patient's history as well as his or her verbal and non-verbal expressions—as a consequence, the orientation of hermeneutic philosophy and semiotics should also be included in the intellectual framework. The aim of this paper is to update the channels of communication between modern neurobiology, psychoanalysis, semiotics and philosophy to the best advantage for their multidisciplinary, holistic cooperation.