The book continues the “School of Self-Knowledge” series, published by the Academy of Self-Knowledge, and is the second volume of the three-volume “Purification”. The first volume was devoted to the study of the very concept of purification and what we purify in ourselves - the organism, the psyche, the body, consciousness? Basically, it was dedicated to Consciousness. The second volume is dedicated to the Soul. “Humanity is slowly forgetting not only what the soul is, but also this word itself. It disappears from everyday life, and modern man prefers to talk about second, third or astral, mental and similar bodies, about the cosmic organism, leptonic essence, field structures... Does this mean that he is not talking about the soul?” “People definitely recognize or recognized the possibility of purifying the soul. The popular language remembers this, it sounds from the lips of people with mystical experience.” “The purification of the soul was somehow constantly correlated with self-knowledge. Movement towards that which is the very core of a person’s personality, whether to consider it the Self or the presence of God in oneself, requires purification.” “If humanity constantly considers the purification of the soul as the purification of consciousness, then does this mean that we are talking about the same thing? Or is there some kind of connection between these two phenomena?” The research in the book is carried out in the vein of cultural-historical psychology, which means that the author examines not just the ideas of philosophers, psychologists, theologians, mystics about the soul, but how this formed the basis of his own his ideas and the ideas of the culture that raised him, and therefore us. Therefore, the book itself is an example of applied purification. For all those interested in self-knowledge, psychology and philosophy.