The new methods of modern sciences can contribute to understand the genesis of mental illness, the disturbances in brain chemistry, physiology, anatomy or genetical information underlying different diseases of the nervous system. Understanding mental illness is not only challenging to science, but is also of great social importance. Moreover, the new developments of neurosciences put new lights on discussions such as brain-mind concepts, unity of mind, definition of consciousness and even definition of the person.For the majority of the scientists, it (...) is clear today that the mind can not be conceived any more as unique and indivisible. For philosophers, it is clear also that neuroscience influenced their vision of life and death: neurosciences are not strange to the debate whole-body death versus whole-brain death for instance. Modern scientific achievements have expanded our vision, allowing us to percieve previously unanticipated interrelationships between biological and psychological phenomena. The boundary between some behavioural and higher neural function studies and biology is arbitrary and changing. It has been imposed not by the natural contours of the disciplines, but by lack of knowledge. (shrink)