Can "existential philosophy" help us understand the causes of "psychological suffering"? Rollo May, one of the pioneers of "existential psychotherapy," in his book "Introduction to Existential Psychotherapy," presents us with a new vision of "psychotherapy" based on the principles of existential philosophy. The book shows how "existential philosophy" is not merely concerned with "therapeutic techniques," but rather raises "deep questions" about "the nature of man" and "the meaning of his existence in the world." May focuses on "basic human experiences" such as "anxiety," "despair," "loneliness," and "isolation," and links them to the "four givens of existence" that humans face: "death," "freedom," and "isolation." And "meaninglessness." May offers "psychotherapists" a new intellectual framework for understanding "patients' problems" and "helping them find meaning in their lives" in light of "existential philosophy."