This chapter begins with brief descriptions of the suicides of Ernest Hemingway & Sylvia Plath in order to introduce the issues that follow. The authors then seek to clarify the meaning of suicide & life-threatening behaviour, & sketch some common patterns in this behaviour. Next, they describe efforts to explain suicidal behaviour or, more precisely, to identify central factors that might enter into an effort to understand such behaviour. The impact that suicide has on individuals and interventions that individuals & social groups can undertake to prevent or at least to minimise suicidal behaviour are explored. Finally, the question of whether or not there could be a rational basis for suicide is examined.