 Some take the persistence question to ask what it means to say that a past or future being is you. This would imply that we can answer it by working out the meaning of terms such as ‘person’, or by analysing the concepts they express. The answer would be knowable a priori if at all. It would also imply that necessarily all people have the same persistence conditions—that the answer to the question is the same no matter what sort of people we considered. Though some endorse these claims (Noonan 2003: 86–92), they are disputed. What it takes for us to persist might depend on whether we are biological organisms, which we cannot know a priori. And if there could be immaterial people, such as gods or angels, what it takes for them to persist might differ from what it takes for a human person to persist.