Because of the increasing incidence of suicide in our society, philosophers, suicidologists, physicians, and ethicists have reflected more deeply on its nature, and as part of this reflection there has been much discussion of what actually constitutes true and authentic suicide and how one is to define it. Some philosophers and ethicists have become rather pessimistic about the possibility of developing an accurate and comprehensive definition of suicide because of the incredibly diverse views of it found in various cultures and traditions. My belief, however, is that these pessimistic appraisals are not entirely warranted and that one can accurately and adequately define it. In what follows, I will first review the various definitions of suicide and then suggest a more adequate definition that will bring a fuller understanding of it. Defining suicide accurately is an important issue for Catholic theology, for if suicide is defined too broadly and comprehensively, then Christ's death could be considered as a suicide. Because his passion, death, and resurrection are normative for Catholic theology, considering his death as suicidal would radically alter Catholicism itself, for if spiritual formation required us to imitate Christ, considering his death a suicide could make suicide morally normative for perfect imitation of Christ. Defining suicide too broadly could have even further harmful consequences for Catholic theology, as it could transform the deaths of the martyrs from self-sacrificial acts undertaken to realize a higher and more perfect good into egotistical and cowardly acts of escape or self-destruction. This would turn some of the most venerated of Christian saints into little more than religious fanatics and self-killers with a religious gloss.