This article discusses the use of professional theories in the field of residential child care. The initial part proposes that professionals by acquiring theoretical insight become more capable of providing adequate support for young people and that there is a need for a multitude of theories. Because care homes accommodate different young people, the professional must alternate between theories and because everyone is a whole person with multiple needs and dispositions, the professional should apply several theories in parallel. The second part substantiates these claims by presenting a number of theories that may be advantageous in the field of residential child care. Together the various theories cover a wide spectrum of issues in young people's lives. The concluding section proposes a new textbook-tradition. The author agues that there is a need for textbooks where most relevant theories are presented thoroughly, where the application of the theories are described and where it is explained how theories may be alternatives to each other or complementary to each other.