Although the most common understanding of suicide is intentional self-killing, this conception either rules out someone who lacks mental capacity being classed as a suicide or, if acting intentionally is meant to include this sort of case, then what it means to act intentionally is so weak that intention is not a necessary condition of suicide. This has implications in health care, and has a further bearing on issues such as assisted suicide and health insurance. In this paper, I argue (...) that intention is not a necessary condition of suicide at all. Rather, I develop a novel approach that deploys the structure of a homicide taxonomy to classify and characterise suicides to arrive at a conceptually robust understanding of suicide. According to my analysis of suicide, an agent is the proximate cause of his death. Suicide is ‘self-killing,’ rather than ‘intentional self-killing.’ Adopting this understanding of suicide performs several functions: We acquire an external standard to assess diverging analyses on specific cases by appealing to homologous homicides. Following such a taxonomy differentiates types of suicides. This approach has application in addressing negative connotations about suicide. As a robust view, adding intention is an unnecessary complication. It is more consistent with psychological and sociological assessments of suicide than ‘intentional self-killing.’ It has useful applications in informing public policy. This paper’s focus is on classifying types of suicides, rather than on the moral permissibility or on underlying causes of suicidal ideation and behaviour. (shrink)