moral obligations are “absolute” and hold unconditionally or whether all obligations are “prima facie,” liable to being overridden in special circumstances, but it is not hard to give examples of acts that most people would consider to be morally obligatory in at least the prima facie sense: refraining from killing an innocent person, telling the truth, refraining from stealing another person’s possessions, keeping a promise. The concept of an obligation is one of a “deontic” family of concepts,