The Observer as an Agent: Relational Quantum Mechanics, QBism, and the Problem of Subjectivity

The role of the observer remains a central conceptual challenge in the foundationsof quantum mechanics. This work examines the observer as an agent whoseparticipation is structurally indispensable for the emergence of physical facts. RelationalQuantum Mechanics and QBism—two influential agent-centered interpretations—recast quantum states, measurement outcomes, and objectivity as relationalor personalist rather than observer-independent. By analyzing their conceptualcommitments, we clarify how these frameworks illuminate the problem of subjectivityand the limits of classical realism.The discussion extends beyond physics to the broader question of whether agencyand subjectivity can be eliminated from scientific and technological practices. Drawingon insights from Pauli, Stapp, and d’Espagnat, we argue that attempts tofully operationalize the observer obscure essential features of experience and understanding.Contemporary artificial intelligence systems exemplify this tension: theydemonstrate high functional performance while lacking subjectivity, intentionality,and responsibility.We suggest that the displacement of the subject—from quantum interpretationto algorithmic decision-making—reflects a deeper structural shift in modern knowledge.Treating the observer as an agent is not merely an interpretive option but aconceptual requirement for coherent accounts of measurement, understanding, andresponsible action in an age increasingly shaped by operational intelligence withoutsubjects.