Depending on whether or not psyche/soma is seen as singular or dual, one may construct different systems explaining man and the world, life and death. In the author's view, the discoveries of psychoanalysis offer a perfectly cogent and unique solution to the famous mind/body problem. In transferring the duality psyche/soma on to the duality of drives, psychoanalysis places the origin of the thought process in the body. In Beyond the pleasure principle, Freud discusses the drastic effect of a painful somatic illness on the distribution and modalities of the libido. He provides a starting point for the Paris Psychosomatic School's psychoanalytical approach to patients afflicted with somatic illnesses. To illustrate the technical implications of this theory the author relates two clinical cases.