The rapid rise of automation and artificial intelligence (AI) has intensified the need for frameworks ensuring that technological progress aligns with human meaningful work and well-being. This paper introduces and rigorously expands upon the Master Work Function (MWF), a novel scalar potential function that quantifies “meaningful work” in hybrid human–machine systems. Drawing inspiration from physics, we formally define the MWF and derive its properties, including a connection to the Jarzynski equality from nonequilibrium thermodynamics for relating work and potential differences. We decompose the MWF into human, machine, and interaction sectors with bounded contributions, and analyze limiting cases (e.g., purely human or machine-driven work) and the interpretation of its gradients and Hessians as signals for optimal human–AI collaboration. Building on socio–technical insights, we formalize the MWF using contemporary mathematics, including scalar field theory, variational calculus, dynamic systems, game theory, and optimal control. We generalize the sectoral decomposition to multi–agent settings and embed the MWF into variational and control frameworks to analyze dynamic trajectories. Jarzynski’s equality is adapted using statistical mechanical arguments to bound the expected work expended during socio–technical transitions. Philosophically, we situate the MWF within phenomenology, critical theory, and justice frameworks, drawing on Rawls, Marx, Husserl, Foucault, and contemporary work on AI alignment and human–machine teaming. Applications are explored across engineering (human-centered design), robotics (human–robot teaming), AI and cyber-physical systems (value-aligned automation), education (AI-assisted teaching), economics (metrics for the future of work), and digital governance. Placeholder sections and tables are provided for empirical validation and simulation results. The paper argues that the MWF can serve as a unifying theoretical and practical tool to ensure that socio–technical systems respect human autonomy, dignity, and flourishing, while enabling efficient and ethically aligned automation.