73 In DF, ethics are set by civilization. Dwarven civilizations, for instace, have [ETHIC:EAT_SAPIENT_OTHER:UNTHINKABLE] and [ETHIC:EAT_SAPIENT_KILL:UNTHINKABLE], meaning that they will refuse to butcher other sapients and also will not eat other sapients that die in battle. Elven civilizations, by contrast, have [ETHIC:EAT_SAPIENT_OTHER:UNTHINKABLE] and [ETHIC:EAT_SAPIENT_KILL:ACCEPTABLE], meaning that while they still will not butcher other sapients, they will occasionally devour the corpses of those they slay in battle (but not under any other conditions). This often puts them at odds with other races.
Also note that these ethics are only set by civilization, not by race. Any creature subsumed into a different civilization will adopt the new civilizations ethics, meaning that elves found living among dwarves will adopt the dwarves' ethics, and that grown-up victims of goblin babysnatchers are, for all intents and purposes, big goblins.