In my recent thinking about the ethics of suicide, I've been compelled to confront a methodological issue in practical ethics that I'd not really given much thought to before now. (Nor, as best I can tell, have other ethicists thought much about the issue either.)
Traditionally, we assign act tokens to one of three deontic categories: forbidden, (merely) permissible, or obligatory. And prior to careful investigation of the morality of an act, our default assumption appears to be that an act is permissible. Furthermore, those who claim the act is either forbidden or obligatory bear the burden of proof to give reasons or arguments in favor of their claims.