The magnum opus of the pioneer of humanistic psychology and co-founder of existential psychology. Using the central concepts of "love," "will," and "fear," it develops approaches to psychotherapy as an art of holistic interaction between therapist and patient. The therapist seeks to understand the patient's existential existence as a whole and to engage in a dialogue with them. "Love and will have become a problem in our time, whereas in the past they were always considered the solution to life's difficulties. We do not exercise our will because we fear that if we choose one thing or person, we will lose others, and we feel existentially too insecure to take that risk. As a result, the connecting emotions and processes, of which love and will are prominent examples, have been stripped of their foundation." "Will is the ability to organize the self in such a way that movement can occur in a specific direction or towards a specific goal. Desire is the imaginative play with the possibility of an act or state.".