New Revised Edition C.G. It describes the years when Jung worked on the Red Book between 1914 and 1930, which he mentioned in 1957 - five years before his death. Although its name has been known to Jung's followers for more than eighty years, the work was not made available to the reader until it was published in 2009. The publication of the book caused great repercussions in the world of psychology. We had the opportunity to read from Jung's own writing how his basic theory, consisting of concepts such as archetype-collective unconscious-persona-anima-animus, emerged. This experience of Jung explains how he personally experienced the "individualization process" that transformed psychotherapy from being just a treatment of diseases into a means of high-level development of personality.