Intended for professionals and trainee counsellors, psychotherapists, counselling psychologists, clinical psychologists and social workers, this book provides a clear and accessible introduction to the theories and methods of the founder of Rational-Emotive Therapy. It presents a concise overview of the life of Albert Ellis, highlighting the events and experiences which influenced him to pursue a career in psychotherapy. The authors go on to discuss Ellis' theoretical and practical contributions to counselling and psychotherapy, looking in particular at the famous ABCs of rational-emotive therapy, the key concepts of ego disturbance, and Ellis' views of therapeutic efficiency. The book also discusses the validity of the most important criticisms of Ellis' work, and the validity of his rebuttals, and the overall influence of Ellis on the field of psychotherapy.