Smart acknowledges that there are no clear divisions between the concepts of disability, society, and the individual. Nevertheless, the book is divided into three parts to facilitate learning. Part 1 is devoted to defining disability and discussing various models of viewing disability. Although the book does not focus on any one disability in particular, chapter 1 defines and describes the four broad categories of disabilities—physical, intellectual, cognitive, and psychiatric. Chapter 2 presents the three basic models used to conceptualize disability: the medical, the environmental, and the functional. This chapter also includes a helpful summary of the Americans With Disabilities Act as well as a discussion of some of the results of the legislation.