162 The purpose of this book has been to present a comprehensive, succinct and practical overview of Reality Therapy. We discussed a wide variety of applications and emphasised their connections with Choice Theory, the underlying theory that justifies the practice of Reality Therapy. To master Reality Therapy, it is necessary to understand the theory. Carleen and William Glasser described these indispensable elements as Choice Theory is the train track on which runs the train of Reality Therapy.