The book has four sections, a design that aids the reader in gaining access to pertinent topics in the midst of a thicket of information. In the introductory section, Chapman defines addiction by describing diverse conceptions of addiction, including the moral, biomedical, and psychological models. The disagreement among experts and society alike regarding which model best depicts the nature of addiction is possibly the most significant ethical and legal issue in the treatment of addiction. Rightfully, this issue resonates throughout the book. Chapman and the authors recommend in the final chapter that the biomedical model, “broadly conceived,” provides the most defensible explanation of addiction. Their explanation of broadly conceived rejects a reductive genetic or neuroessentialist concept of addiction that negates the crucial role of social, environmental, and cultural factors. Moreover, the authors disavow the notion that individuals with addiction disorders lack control over their decision making and, consequently, hold them responsible for their behavior. This position echoes an emerging consensus among scientists and ethicists that addiction is subject to gene-gene and gene-environment interaction, and individuals with a family history of addiction may circumvent their genetic vulnerability by avoiding or limiting drug exposure. Even those ethicists who maintain that the risk-taking propensity of persons with addiction involves a somewhat impaired capacity for decision making should encounter scant disagreement with the authors’ defensible position.