Mark Siegler, the guest speaker at the IV Josep Egozcue Conferences, dedicated this cycle of lectures to discussing the three ages of medicine and the doctor-patient relationship. During the first lecture he focused on the transformation that the relationship with the patient has undergone throughout history. During the second lecture he talked about the past and future contributions of clinical ethics. He developed this term to refer to ethics applied in the practice of medicine. Several other experts enriched the debate with their contributions to the discussion.