Psychological Foundations
Sigmund Freud, the "Father of Psychoanalysis," revolutionized how we think about the self. He identified three levels of consciousness (conscious, preconscious, unconscious) and three parts of your psyche: Id pleasure−seeking, Ego reality−based, and Superego (moral conscience).
Gilbert Ryle rejected the mind-body separation, arguing "the self is the way people behave." Instead of "I think, therefore I am," he'd say "I act, therefore I am." Your self isn't hidden inside you - it's visible in everything you do.
George Mead developed the social self theory - you're not born with a self, but develop one through social interactions. He identified two sides: the "Me" (learned behaviors from society) and the "I" (your spontaneous, unsocialized responses).
Paul Churchland takes a purely scientific approach: "the self is the brain." No brain, no self. Meanwhile, Maurice Merleau-Ponty argues the self is embodied subjectively - the mind-body split is pointless because they're inseparably connected.
Reality Check: Modern psychology shows that your sense of self comes from complex interactions between biology, psychology, and social experiences.