The problem of personal identity is concerned with the question of how an individual can remain the same person over time, despite undergoing various changes in their physical and psychological characteristics.

Plato's 'Ship of Theseus' thought experiment involves replacing all the parts of a ship one by one, raising the question of whether it remains the same ship.

Self-consciousness refers to the ability of an individual to be aware of their own mental states, including thoughts, feelings, and experiences.

David Hume's bundle theory of the self posits that the self is not a unified entity but rather a collection of mental states that are constantly changing.

Metacognition refers to the ability of an individual to think about their own thinking, including their thoughts, feelings, and actions.

René Descartes' famous statement 'Cogito ergo sum' ('I think, therefore I am') is a foundational principle of his philosophy, emphasizing the certainty of one's own existence.

Self-awareness refers to the ability of an individual to recognize and understand their own existence, thoughts, and feelings as distinct from those of others.

George Herbert Mead's theory of the self emphasizes the role of social interactions in shaping an individual's sense of self.

Empathy refers to the ability of an individual to understand and share the feelings, thoughts, and experiences of another person.

Paul Ricoeur's theory of the self emphasizes the role of narrative in shaping an individual's sense of self.

Autonomy refers to the ability of an individual to make choices and act in accordance with their own values and beliefs, independently of external influences.

Ludwig Wittgenstein's later philosophy emphasizes the role of language in shaping our understanding of the self.

Existential angst refers to the feeling of anxiety or dread that arises from contemplating one's own mortality and the meaninglessness of life.

Judith Butler's theory of the self emphasizes the performative nature of identity, arguing that the self is shaped through our actions and interactions with others.

Emotional awareness refers to the ability of an individual to recognize and understand their own emotions and feelings.