When we feel bad and are unable to achieve what we would like in both our personal and professional lives (or sometimes even end up with what we don’t want), it is not only due to reality as it is, but often because of how we perceive reality through our own lens. The ancient philosopher Epictetus already recognized: It is not the things themselves that disturb people, but the perspective they have on those things. From this insight, New York psychotherapist Albert Ellis developed the last major school of psychotherapy of the 20th century, Rational Emotive Therapy (RET), which led to the cognitive shift in behavior therapy but, with its philosophical foundation, goes far beyond conventional behavior therapy and stands rather between it and depth psychological approaches. The book clearly and understandably illustrates this connection.