This study introduces Blended-Self Theory, a novel cognitive-linguistic framework coined by the author to analyze how literary narratives construct character identity through the fusion of inner and outer worlds. The theory posits that a character’s thoughts, emotions, and bodily experiences are not isolated from their environment; rather, they dynamically interact with natural, social, and material elements to form a unified, emergent self. Grounded primarily in Cognitive Grammar (Langacker, 2008), Blended-Self Theory uses mechanisms of profiling, figure-ground organization, attentional distribution, and embodied construal to trace how language encodes the blending of internal and external experiences. The theory is applied to selected literary texts, including The Snow Child (Riggs, 2012), All the Light We Cannot See (Doerr, 2014), and Blake’s The Sick Rose (1794), illustrating how characters’ identities are co-constructed with their environments through textual and linguistic cues. By formalizing the interaction between cognition and environment in literary analysis, Blended-Self Theory provides a systematic, replicable framework for studying the emergence of selfhood in narrative discourse, bridging cognitive linguistics, literary stylistics, and embodied cognition.