None of these issues can be settled until the authors determine what addiction is, which is the task of this chapter.
Clinicians debate whether addiction is a disease (Heyman 2009; Hyman 2005; Leshner 1997; Pickard and Pearce, in press). Philosophers and lawyers argue about whether addicts are morally or legally responsible (Sinnott-Armstrong, in press). Scientists disagree about which drug users to include in experimental studies of addiction. People wonder whether their friends or they themselves are addicted—and what that means. None of these issues can be settled until we determine what addiction is. Th at is the task of this chapter.