Mikhail Lvovich Pokrass is a famous psychotherapist, founder of his own psychotherapeutic school, author of the book “Behavior Therapy.” It provides a definition of five categories of psychology. The fourth category is “MOTIVE.” “It is a tool for studying the “driving springs” of human existence, experiences and behavior. Here we study the goals, programs of human behavior, his needs, feelings, emotions, instincts, impulses, drives, and human life itself.” It is this category of psychology that became the main subject of the author’s research in the book “The Guarantee of the Possibility of Existence.” This book is difficult to attribute to any one literary genre: it is a serious scientific research, and passionate journalism, and a detailed clinical description, and fictionalized notes... But in general, this is a book about the fact that each of us has the talent to live happily and about why most of us do not know how to use this talent. This is a book for anyone interested in themselves. Oneself as “Homo moralis”, as “an animal that stands apart in society.”