The book retains the same chapter structure and general lines of argument. We have also retained the chapter headings from the second edition, with a few exception (for example, Refused of Treatment and Relevant Properties). Material under deleted headings has been relocated under different headings. The main innovation is the introduction of large bodies of entirely new material throughout every chapter. Various topics such as AIDS and artificial nutrition and hydration have been included and our arguments have been extended and deepened throughout.