“Disease is usually a binary system: either you’ve got it or you don’t. Pneumonia: got it or you don’t. HIV: got it or you don’t. Multiple sclerosis, polio, emphysema—all of these are yes-or-no propositions. But alcoholism is not, in fact, a disease: it is a behavior, or perhaps a collection of behaviors. And because nobody can say for sure whether a behavior has ever been eliminated for good without a crystal ball, we must first establish a baseline definition of what success looks like in the treatment of addiction. I’ll propose this simple definition: A treatment for alcoholism may be called successful if an individual no longer drinks in a way that is harmful in his or her life.”