<p>This article introduces the Theory Biography Framework (TBF), a six-stage approach to understanding theories and artworks as conceptual life. Rather than treating theory as a static tool, the framework traces how theoretical forms emerge, attach, endure, transform, and recur through Birth, Linkage, Integration, Expansion, Succession, and Fading. Applied to Leonardo da Vinci’s Mona Lisa, the framework reads the painting not as a fixed icon but as a theoretical agent whose unfinished surfaces, enigmatic smile, and cultural afterlife enact a living ontology. Through this case, the article shows how incompletion functions as generative openness, ambiguity as relational attachment, historical circulation as affective endurance, and fading as conceptual latency. Drawing on work in embodied cognition, affective aesthetics, historical feeling, selective explanation, and narrative identity, the article argues that aesthetic explanation is strongest when it attends to how theories live. The Theory Biography Framework thus offers a selective, portable ontology for tracing theoretical life across art.</p>