In philosophy, the matter of personal identity deals with such questions as, "What makes it true that a person at one time is the same thing as a person at another time?" or "What kinds of things are we persons?" The term "identity" in "personal identity" refers to "numerical identity," where saying that X and Y are numerically identical just means that X and Y are the same thing. Personal identity is not the same as personality, though some theories of personal identity maintain that continuity of personality may be required for one to persist through time. In relation to answer questions about persistence, such as under what conditions a person does or does not continue to exist, contemporary philosophers often seek to first answer questions about what sort of things we are, most fundame