Emil Durkheim classifies suicide, from the viewpoint of social phenomenology, into four kinds: egoistic, altruistic, anomic, and fatal suicide. There are cases such as self-sacrifice, martyrdom, and patriotic martyrdom, in which the good of the other, of the national community, or of a religious group is chosen through discernment between the good of one’s own life and the greater good which the agent intends. I think, however, that it is more appropriate to call these acts devotion or self-sacrifice rather than suicide. For these altruistic acts are motivated by the greater good of the other or of a community, not by the desire or intention to take one’s own life. I am in agreement with the view of rule utilitarianism that the rule and social idea of suicide-prohibition diminish the “Werther effect” and maximize both the utility for the social community and the life-good of the actor. Even so, rule utilitarianism cannot provide a justification for the grounding of this rule, because ultimately it is grounded in experience. I believe that the rule of suicide-prohibition can be justified by a realism which deliberates on the effects of the act and on the act itself, based on the facts in their subjective and objective dimensions. Consequently we may say that suicide motivated and intended by free will cannot be justified at all, just as in the case of homicide. On the other hand, so-called altruistic suicide can be justified as a good act, if it satisfies the conditions for the application of the principle of double effect.