This book provides an overview of Orthodox Psychotherapy, which is the art and science of healing the soul. In contrast to Western psychologies and therapies, which are principally symptom-relief oriented, the emphasis in Orthodox Psychotherapy is holistic. This approach has extensively established and confirmed benefits, and was also once the unquestioned orthodoxy of the Western medical tradition for the two millennia prior to the nineteenth century. The foundational and critical tenet of Orthodox Psychotherapy is that pathologies are the product of a darkened nous and an impure heart. When a person is inwardly healed, when the noetic part of the psyche is purified and the nous is freed; spiritual, psychological, emotional, developmental, and other pathologies, characteristically disappear. The text provides the student and inquirer with definitions of the related Greek terms and patristic concepts, and discusses: (a) the psyche and the nous, (b) pathology, (c) fantasy, (d) emotions, (e) the movement of the nous, (f) the etiology of disorders, (g) the 'cycle of temptation', and (h) neptic treatment and its implications.