Adler, the optimistic doctor, who never gave up trying to find a means of treating the patient, has since devoted himself to the meticulous examination of the nervous character. The findings of this research are presented in this book. His fellow doctors rightly characterized every mentally ill person as having a nervous character, because indeed, as demonstrated in this book, the nervous character is the prerequisite of every mental illness, which is nothing more than a property or a symptom of the nervous character. On the nervous character, at some point in an individual's life, both neurosis and psychosis manifest. Therefore, if we want to understand mental illness, we must know the nervous character. This was precisely what the doctors of his time ignored, saying only to the patients, "You have nothing, you are just nervous." But what does a nervous person mean? How is it formed and how is it corrected? These questions were not answered. Adler provided the answer through this book. [Excerpt from the text on the back cover of the edition]