The paper first reviews previous works, which include research on the existential meaning of caring, examination of the hermeneutic phenomenological method, and exploration of the meaning of medical ethics. There is a certain tension and a possible loosening between phenomenology and psychology due to Husserl’s transcendental phenomenology and Heidegger’s fundamental ontology with the implication that the concept transcendent needs to be correctly seized upon. On this basis, ethical issues pertaining to mental health nursing in Taiwan are discussed through examination of three psychiatric nursing and therapy studies relating to spirit possession in psychiatric patients, the emotional expressions of families of the psychiartric patients, and the social constructions of psychiatric patients. The first takes a hermeneutic phenomenological position, but does not make use of phenomenological methods and thus cannot discover the essential cause or the cure for the illness. The second study possesses a phenomenological attitide, but the method is not phenomenological. The final study makes use of qualitative field data and corresponds with the idea of vita active, which Hannah Arendt emphasizes. The article concludes by expanding the content of phenomenology from Husserl, and Heidegger via Hans Jonas to Arendt with variations in methodology and (subject matter). Possible synthesis of phenomenology and psychology from the viewpoint of Arendt is discussed.