Writer and journalist Ted Harrison asks what body, soul and self really mean in the light of advances in our understanding of molecular biology. Can the Cartesian idea of body-soul dualism mean anything today? Twenty years ago Ted himself received a life-saving kidney transplant. He reflects on how he views the donor organ - and the unknown friend who donated it and he asks whether the development of organ and tissue transplantation changes our notions of the integrity of the body. Producer: Charlotte Simpson.