This article analyzes Machado de Assis’s short story O Espelho (1882) from the perspective of moderate semantic holism, arguing that personal identity can be understood as a discursive phenomenon whose stability depends on networks of belief, practices of recognition, and context-sensitive semantic anchors. Rather than adopting a psychological reading focused on inner life, the paper interprets Jacobina’s crisis as a semantic destabilization of self-reference: when the social practices that name and confirm him withdraw, the meaning of the self becomes blurred and indeterminate. The military uniform functions as a re-anchoring device that restores identity by reorganizing a contextual economy of relevance. On this view, the story operates as a literary laboratory for examining the semantic dependence of the self and the fragility of identity once its discursive conditions collapse.