A view of human functioning is presented in which functioning is seen as integrating head and heart, emotion and reason, in a process by which people are constantly making sense of their lived emotional experience to form narratives of told experience. Because much of the processing involved in the generation of emotional experience occurs independently of and prior to conscious thought, therapeutic work on a purely cognitive level of processing is unlikely to produce enduring emotional change. The questions especially relevant to psychotherapy are how we can best facilitate change in emotions rather than only changes in cognition or behavior. A theory of emotional change is presented in which change in emotion is seen as requiring that first emotions be felt and then they both be exposed to new emotional experience and be reflected on to create new meaning. The process of emotional change thus involves both new experience and new understanding. At times, people also need to protect themselves from being overwhelmed by emotions. They need to be helped to tolerate and regulate them so that emotions inform their lives rather than control them. The importance of both emotion awareness and emotion regulation in therapeutic change is thus highlighted. The article ends by reviewing research on the role of emotional processing in therapeutic change and presents six empirically based principles of emotional processing that will help move the field toward psychotherapy integration in a manner that clearly recognizes emotion as a key component of functioning and change.