Personal identity

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 fundamentally. Many people claim we are animals, or organisms, but many others strongly believe that no person can exist without mental traits, such as consciousness. Since an organism can exist without consciousness, both these views cannot be true (if we are organisms we can exist without being conscious; but if we can't exist without consciousness, we are not organisms). Thus, in order to determine whether certain features (such as consciousness) are crucial to a person's continued existence, it may be important to first ask what sort of things we are.

Generally, personal identity is the unique numerical identity of a person in the course of time. That is, the necessary and sufficient conditions under which a person at one time and a person at another time can be said to be the same person, persisting through time;

In contemporary metaphysics, the matter of personal identity is referred to as the of personal identity. The concerns the question of: What features and traits characterize a person at a given time. In Continental philosophy and in Analytic philosophy, enquiry to the nature of Identity is common. Continental philosophy deals with conceptually maintaining identity when confronted by different philosophic propositions, postulates, and presuppositions about the world and its nature.

One concept of personal persistence over time is simply to have continuous bodily existence. However, as the Ship of Theseus problem illustrates, even for inanimate objects there are difficulties in determining whether one physical body at one time is the same thing as a physical body at another time. With humans, over time our bodies age and grow, losing and gaining matter, and over sufficient years will not consist of most of the matter they once consisted of. It is thus problematic to ground persistence of personal identity over time in the continuous existence of our bodies. Nevertheless, this approach has its supporters which define humans as a biological organism and asserts the proposition that a psychological relation is not necessary for personal continuity. This personal identity ontology assumes the relational theory of life-sustaining processes instead of bodily continuity.

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